Specna Arms SA-F21 FLEX™ Carbine AEG; FALCON EFCS Edition

The Specna Arms FLEX™ is a great beginner gun for new Airsoft players, it offers a compact lightweight design that is ideal for new players who are not used to carrying around heavy gear for long periods. This lightweight construction also makes it a great spare primary for any experienced skirmisher looking for a reliable polymer AEG that they can use after their arms are spent and they need something easier to carry whilst they manoeuvre around the battlefield.

Starting at the front end we can find a pre-installed aluminium suppressor which covers the 330mm 6.03mm tightbore inner barrel, mounting to the 5.5-inch alloy outer barrel. This gives the SA-F21 FLEX™ the look of an integrally suppressed AR with a compact front end which makes it easy to take corners in CQB. The suppressor mounts to 14mm CCW male threading but due to the inner barrel length, a barrel extension will be required to mount a tracer unit.

Surrounding the outer barrel we find a functional polymer M-LOK rail handguard. The functional sections are at the 3, 6 and 9 o'clock positions on the handguard, aftermarket M-LOK accessories and rail sections are compatible and can be attached to these sections. Within this handguard is a 6.03mm diameter inner barrel, which offers superb accuracy potential.

The 12 o'clock position of the polymer handguard provides a full-length 20mm Picatinny rail which integrates seamlessly with the receiver rail to allow for various optics to be mounted and paired with one another atop your rifle. The full-length Picatinny rail is an excellent feature as it maximises the rail space, whilst keeping the AEG very compact and versatile with its customisation ability so you can get it geared up for any tactical operation. 

Sitting atop the 20mm Picatinny rail we find some preinstalled iron sights. The front sight has an adjustable elevation and the rear sight has an adjustable windage, both can be adjusted by twisting the turrets on the right of the sights. The sights can be deployed by flipping them up, which will snap them into their upright position. When up, the rear sight has a choice of two eye hole sizes, this allows you to engage easily with targets at different ranges by selecting the best-sized hole that gives you pinpoint accuracy. To stow the sights, simply push them back down and they will flip into place. When flipped down, the iron sights offer back-up pistol-style open iron sights for one-armed use.

Moving rearward we reach the receiver, which has a familiar M4/AR-15 layout and is constructed from high-density polymer. The ambidextrous fire selector is located on both the left and right side of the AEG, sitting directly above the pistol grip to provide fast and easy access for both right and left-handed shooters. The fire selector has a 90-degree throw between modes and makes a satisfying click when in position. It is quick to operate and the tactile click into place ensures you won't accidentally knock it and end up in the wrong fire mode. Each fire mode is indicated with recessed markings reading SAFE/SEMI/AUTO.

Located dead centre on the left side of the polymer receiver we find a dummy bolt release catch which doesn't have a function on this Airsoft AEG but is included regardless to keep the externals looking realistic. The magazine release is on the right side of the magazine well and is ideally positioned to be pressed with the trigger finger of a right-handed user. The design surface of the button is textured to provide the necessary gripping qualities for fast mag swapping.

The HOP-up unit is located in the mock ejection port. This part allows you to adjust the amount of "HOP" applied to your BBs so you can tune the SA-F21 specifically for your ammo weight of choice, to achieve the flattest possible trajectory. The Rotary HOP-up unit can be accessed by holding the charging handle back, after which the dust cover will spring open and the mock bolt plate will retract. The rotary HOP-up design is known as the latest and greatest for M4 AEGs, and it retains the HOP-up settings better than previous adjustment styles and allows for finer tuning.

Moving downwards we come to the rifle's pistol grip. This grip features an ergonomic angle that is comfortable to hold in all stances such as running around the battlefield or engaging opponents. All four sides of the grip offer a textured surface, on the left and right there is a rough texture, and on the front and back of the pistol grip there is a ridged texture. When combined in your hand, these two textures provide the secure grip you need to maintain pinpoint accuracy for both gloved and un-gloved users.

Following the receiver, we reach the AR buffer tube, which is constructed from a strong alloy and provides 6 positions of adjustment, enough to suit any body type or loadout. To adjust the stock position, press up on the lever located at the rear underneath, then slide the stock to your desired position. The stock is constructed from high-density polymer and features a rubber butt plate, which provides comfort and security when wearing full-body gear and operating from modern shooting stances. The buffer tube system is compatible with most aftermarket M4/AR-15 stocks. If you fancy a change or get tired of the SA-F20's standard look in the future, you have access to the widest variety of aftermarket stock options out there! At the rear of the stock, we are treated to a QD sling point on both sides, this allows you to attach a sling to either side of your rifle depending on your shooting style.

The battery compartment is located within the buffer tube and can be accessed by removing stock. To do this, pull the two polymer tabs down which are located on either side towards the front of the stock. Once pulled down, the polymer stock can slide off the buffer tube and you can access the Deans style connector. For the Specna Arms SA-F20 FLEX™ Compact Carbine AEG, we recommend an 11.1V 1450mAh 30c Stock Tube Battery, however, you may not be able to fully collapse your stock with this battery so be careful. The package also includes a Deans to Mini Tamiya if you would prefer a different battery.

On the inside, we are treated to some good pre-upgraded internals. The gearbox shell is reinforced to cope with stronger springs and the spring guide is a quick change example making power tuning a breeze. Inside the version 2 gearbox, we have a steel piston with a full rack of steel teeth and a tappet plate to guarantee reliable feeding. The gearset is constructed from steel with an 18:1 ratio, and the gears themselves run on 8mm bushings for a smoother, unlaboured gearbox report. 

The FALCON EFCS Fire Control System comes pre-installed in the SA-F21 FLEX™ version 2 gearbox. Usually only seen in custom builds and high-end AEGs this feature is a fantastic inclusion, giving you options for 1-5 round burst mode, a binary trigger, as well as various wiring and battery protection features to boot. The 1-5 round burst mode and binary trigger settings can also be set at the same time, with binary being used to replace semi-auto mode, and 1-5 round burst replacing the full auto mode. The fire control system is designed to be used with Li-Po batteries and prevents the replica from firing when it detects a current draw spike, or if the battery voltage is too low. Please note that when low-voltage batteries are used with the SA-F21 the gearbox can lock up regularly. The EFCS fire control system can be programmed using simple trigger pulls and requires no external tools, special adapters, or a PC to function. For more information please see the Special Instructions Section.

For those who are fresh to the game of Airsoft or maybe a veteran Airsofter in the market for a lightweight backup platform, the Specna Arms SA-F21 FLEX™ Carbine AEG; FALCON EFCS Edition is ideal for all your needs. With its compact build, tactical looks, and good preinstalled internals including the programmable FALCON EFCS MOSFET, the SA-F21 FLEX™ is a great all-purpose platform with plenty of room to accessorise and upgrade!

Features

• 6.03mm Tightbore inner barrel - Great accuracy potential
• Suppressor included - keep it tactical and stealthy!
• 14mm CCW Male threaded outer barrel - Tracer/suppressor ready
• Flip-up adjustable iron sights pre-installed - Mounted to the top rail
• M-LOK style handguard
• Extended charging handle latch - Easy access to the HOP-up unit for adjustment
• 20mm Picatinny railed receiver - Ready for a red dot sight or rifle scope
• Rotary adjustable HOP-up unit - Easy to adjust in fine increments, holds its setting well long-term
• 6-Position M4/AR-15 buffer tube - Adjust the stock to suit your body type perfectly
• QD sling sockets on each side of the stock
• Ergonomic pistol grip - Great for modern shooting stances, very comfy
• Reinforced version 2 gearbox
  • 8mm Bushings
  • Steel 18:1 gearset
  • Quick change spring guide
• FALCON EFCS MOSFET preinstalled - see programming below
• Rear wired Deans connector - recommended 11.1V 1450mAh 30c Stock Tube Battery
• Compatible with M4/AR-15 AEG magazines - Plenty of spares available

Package Includes

• Specna Arms SA-F21 FLEX™ Carbine AEG; FALCON EFCS Edition
• 2x Mid-cap 170rnd magazines
• Cleaning rod
• Deans to Mini-Tamiya

Special Instructions

Please note that the gun's EFCS system is only compatible with LiPo Batteries, and is not compatible with LiFe or NiMh batteries.

Please note that both binary fire and burst modes can be set, as binary fire is applied to semi, and 1-5 fire mode is applied to full auto.

Please note that fitting the supplied deans connector will constitute a modification of the replica, and if you carry out this modification you will not be able to return your replica. 

FALCON EFCS Protection Feature

Gearbox Protection

When the current is too high or abnormal the power supply on the EFCS will disconnect to protect the motor and battery, and the motor will vibrate three times.

If the voltage of the battery is too high the EFCS power supply will automatically disconnect and the motor will vibrate twice.

Battery Protection

The FALCON EFCS has an operating voltage between 6-13v. If the voltage is too low or too high the power supply will be cut. If the voltage of your battery is too low, the FALCON will notify the user via 5 vibrations, then cut the power to protect your battery. 

Vibration Description

• 1 - Power On
• 2 - System Error
• 3 - Voltage too high
• 5 - Low Voltage

Falcon Electronic Fire Control System

1-5 Shot Mode

• Set the fire select to SAFE.
• Pull the trigger and hold for 3 seconds to enter programming mode, and release when the motor makes a sound.
• Pull the trigger once and release to enter 1-5 shot programming mode, release when the motor makes a sound.
• Pull the trigger 1-5 times depending on the amount of shots you want a single trigger pull to make.
• Set the fire select to full auto.

Trigger Sensitivity

• Set the fire select to SAFE.
• Pull the trigger and hold for 3 seconds to enter programming mode, and release when the motor makes a sound.
• Pull the trigger twice and release to enter sensitivity programming mode, release when the motor makes a sound.
• Pull the trigger between 1-3 times for different levels of sensitivity.
  • 1 - Highest Sensitivity
  • 2 - Standard Sensitivity
  • 3 - Low Sensitivity

Binary Fire Mode

• Set the fire select to SAFE.
• Pull the trigger and hold for 3 seconds to enter programming mode, and release when the motor makes a sound.
• Pull the trigger three times and release to enter bump fire programming mode, release when the motor makes a sound.
• Set the fire selector to semi-auto
• Repeat the same process to disable bump fire

Reset to Default

• Set the fire select to SAFE.
• Pull the trigger and hold for 5 seconds to reset all settings.