The Jefftron Leviathan compatible with Version 3 gearbox is one of the most advanced microprocessor-controlled ETU (electronic trigger unit) boards on the airsoft market! The Jefftron Leviathan V3 Optical monitors the gear position in real time using two optical sensors. The Leviathan board can be easily programmed via Bluetooth connection using a smartphone (iOS or Android).
With the included foam pad that can be attached to the AK trigger mechanism, the trigger travel can be adjusted to be extremely short, achieving a so-called "hair trigger".
The Leviathan V3 Optical unit supports RFTS technology (Unique Real Feel Trigger System), where a separate spring mechanism simulates the trigger response of a real AK74. Jefftron collaborated with a gunsmith specialized in firearms to achieve a realistic trigger feel in the RFTS design.
The Leviathan series offers various expansion options through an output port on the board. (Installing additional accessories requires soldering on the PCB. Please leave modifications to a professional.)
The Leviathan brings a wide range of completely new features to your AEG and improves existing ones. With this unit, you can control your gun’s fire modes, rate of fire (ROF), pre-cocking, active braking, protect LiPo/LiFe batteries from over-discharge, and much more.
The Leviathan unit is fully installed inside the Version 3 gearbox, replacing the traditional trigger switch contacts. The unit comes with pre-installed complete wiring, including a 40A mini fuse and Deans/T-connectors. No soldering is required for the basic installation!
What features does the Leviathan unit provide?
- Adjust and add all fire modes to any selector position (SAFE - SEMI - AUTO).
- Three different burst fire modes. Each mode’s burst length can be set between 2 - 20 shots.
- Option to stop firing when the magazine is empty. Magazine change can be signaled to the gun via an additional switch (sold separately).
- Limit the gun’s rate of fire by adding pauses between shots while maintaining an extremely fast trigger response, even when full-auto speed is reduced by software.
- Adjustable active brake strength, which can also be disabled.
- "Pre-cocking" function for instant and delay-free semi-auto shots.
- Option to add a delay between shots to simulate the effect of firearm recoil on shooting speed. Delay can be set between 0.1 - 4 seconds.
- Low voltage warning for LiPo or LiFe batteries. Works with 2S - 4S LiPo and 3S - 4S LiFe batteries.
- User can save multiple configuration profiles.
- Software displays actual battery voltage with a color-coded indicator for charge level.
- Three separate shot counters: total lifetime shots, user-resettable counter, and one that resets when the battery is disconnected.
- Error log records all errors during the unit’s lifetime.
- Leviathan V3 monitors current, voltage, and temperature, protecting components from damage in case of failure.
- Motor vibrates and beeps to provide feedback to the user.
- Programming settings are saved in real time to the Leviathan V3 memory unit, so you won’t lose settings if Bluetooth disconnects or the battery is removed during adjustment.
Programmable fire modes:
Each fire mode below can be assigned to any selector position (SAFE - SEMI - AUTO).
- SAFE: Trigger pull does nothing, gun is on safe.
- SEMI: Fires one shot per trigger pull.
- SEMI/BurstX: Short pull fires one shot, long pull fires a preset burst.
- "Double trigger": Fires once on pull and once on release (two shots per trigger cycle).
- BurstX: Fires a burst with one trigger pull.
- BurstX/BurstY: Short pull fires burstX, long pull fires burstX followed by burstY.
- BurstX/Full: Short pull fires burstX, long pull fires full-auto.
- Full: Fires full-auto as long as the trigger is held.
- Virtual reload: Pull the trigger to virtually reload the magazine.
SPECIFICATIONS:
- The Leviathan electronic board is coated with lacquer for water protection.
- Pre-cocking function requires an anti-reversal latch to prevent gear backspin.
- Designed to operate and withstand up to 17V batteries. Compatible with 8.4 - 12V NiMH and 7.4 - 14.8V lithium-based batteries.
- Parts removed from the gearbox during installation: cut-off lever, original trigger, switch contacts, and safety parts. Original trigger can still be used with the Leviathan board.
Leviathan manual: Download the installation and user manual HERE
Download the Leviathan app: https://www.jefftron.net/application
Package Includes:
- Leviathan - V3 Optical with Deans/T-connector and 40A fuse slot. Motor wires with standard motor connectors.
- Screw set for securing Leviathan inside the gearbox.
- Foam pad for trigger sensitivity adjustment.
- RFTS mechanism for realistic trigger feel.
- English installation guide.

https://youtu.be/fIbqSugvzbU
SAFETY INSTRUCTIONS:
- Installing the board inside the gearbox requires understanding of airsoft gun mechanics and technical skills.
- Read the manual before installing the Leviathan unit to avoid damage!
- Short circuit or incorrect battery connection will immediately destroy the unit! Incorrect wiring voids the warranty and may cause the battery to explode!
- Always disconnect the battery when the gun is not in use! Otherwise, the board may slowly drain the battery, rendering it unusable. When connected, Leviathan draws a small standby current.
- Always ensure the barrel is pointed in a safe direction before connecting the battery!
- Do not modify, repair, expose the Leviathan V3 board to liquids or heat.