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JeffTron Leviathan Airsoft Drop-In Programmable MOSFET Module (Type: V2 Optical - Blue Speed Trigger / Wired to Stock)

4.5 stars, based on 20 reviews
JeffTron Leviathan Airsoft Drop-In Programmable MOSFET Module (Type: V2 Optical - Blue Speed Trigger / Wired to Stock)
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Gearbox shell not included
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  • Easy installation inside the gearbox version 2, compatible with Tokyo Marui standard
  • You dont have to modify the gearbox V2 from the Krytac company. Simply cut the Leviathan bottom board
  • It uses optical sensor actuated by sector gear cam for perfect semi and burst fire timing
  • For fire selector position is used optical sensor too - it works with sticker provided with Leviathan
  • Tactile trigger switch makes short click for great hair trigger mod
  • Unique real feel trigger system (RFTS) simulates trigger feeling like in the real gun. It adds secondary resistance with release after the fire. Feeling is comparable to shooting with real caliber 22lr in AR15
  • Completely made wiring allows the fastest and the easiest installation into the gun, it is long enough for all kind of weapons with battery placed in the stock. No soldering is needed
  • On the board is input port for controlling output port, 3rd burst, external trigger, magazine reload, etc. and output port for the hop-up chamber BBs illumination, powering electric magazine, flashlight, laser, etc.
  • Specified for common batteries up to 17V (Ni-xx 8.4 - 12V, lipo 7.4 - 14.8V)
The Leviathan - V2 optical is one of the most advanced ETU (electronic trigger unit) on the market.

It combines optical and switch sensors for better handling and durability.

Build-in wireless communication for quick setup using iOS or Android smartphones!.

Tactile trigger switch has travel only 0,13mm long for ultimate hair trigger feeling.

Unique Real feel trigger system (RFTS) with integrated spring simulates trigger resistance like in the real gun. It adds secondary resistance with release after the fire. RFTS was designed by professional gunsmith for more realistic feel from shooting.

External output and input port serves for custom accessories.

Real time response for change settings -> immediately test result.

Easy installation into the gearbox (fully integrated inside the gearbox instead of the original trigger contacts).

New functions are for free for every user via online update.

Main Functions:

  • Adds new shooting modes independent for every position on the fire selector (SAFE - SEMI - AUTO)
  • Three adjustable bursts (range 2 - 20 shots)
  • It preserves empty magazine detection like the original gun
  • Rate of fire can be reduce to 40%. It add breaks between shots to reduce RoF. It gives fast trigger response even with very low rate of fire, just like in a real gun.
  • Adjustable strength active braking (can be disabled)
  • Pre-cocking function for instant shot on SEMI fire
  • Delay between shots adds time in which isn't possible to shoot, it simulates the delay from gun reload or recoil (range 0,1 - 4,0 seconds)
  • Electronic fuse set sensitivity for high current detection to avoid any damage if something goes wrong
  • Low battery indication for 2S - 4S li-pol and 3S - 4S li-fe
  • Virtual magazine simulates low capacity magazines, it will force the gun to stop shooting when it reach 0. There can be set warning after shot before empty magazine and how it will be reloaded
  • On the board are input and output ports for controlling external devices or Leviathan
  • Statistics screen shows shooting output with cycle timing, motor current consumption, rate of fire and temperatures. It allows you to do fine-tune gearbox upgrade
  • Application shows actual battery voltage value. Color lines indicates battery charge status where green is OK, orange will warn after each shot and red will not allow to shoot
  • User can save multiple settings under profiles
  • Update function fixes bugs and adds new features to the device
  • There are three shot counters. Total count every shot during the device lifetime. User counter can be reset by user anytime. Power-up counter is reset by battery connection
  • Error log shows errors made during the device life also can be erased by user
  • For better security wireless connection can be disable by the selector switch (can be deactivated)
  • Leviathan monitors current, voltage and temperature to avoid any damage when something go wrong
  • Motor vibrates and beeps as a feedback for user
  • Programmed settings are saved in the Leviathan memory immediately after their change, so you can immediately test it and settings aren't lost when is battery disconnected or lost connection with smartphone
  • New functions are for free for every user via online update function


Independent for every position on the fire selector (SAFE - SEMI - AUTO)
  • SAFE: no responding on the trigger pull.
  • Semi: it fires single shot per trigger pull.
  • Semi/BurstX: short trigger pull fires single shot, long trigger pull fires burst.
  • Binary trigger: it fires single shot when trigger is pulled and another single shot when is released.
  • BurstX: gun shoot burst per trigger pull.
  • BurstX+BurstY: short trigger press fires burstX, long trigger press makes burstX+burstY fire.
  • BurstX/Full: short trigger press fires burstX, long trigger press makes auto fire.
  • Full: gun makes auto fire until releasing trigger.
  • Virtual reload: pull trigger to reload virtual magazine

Manufacturer: JeffTron


Mobile Application: You can install it HERE
Device Instructions: You can download installation manual in English HERE [PDF]
Compatibility: M4, M16, HK416, AR15 with V2 gearbox according to TM design, M4 with V2 gearbox from Krytac, SR25 with V2 gearbox according to TM design, MP5 with V2 gearbox according to TM design, G3 with V2 gearbox according to TM design, M249 with V2 gearbox according to TM design, M107 BARRETT from Snow Wolf, and others. NOT COMPATIBLE with KWA gearbox V2.5, S&T or Arcturus gearbox V2, ICS SSS gearbox V2, Ares Amoeba gearbox V2, G&G G2 gearbox V2, APS eSilver edge gearbox V2, and Gearbox V2 with microswitch
Package Includes: Leviathan - V2 optical drop-in electronic module with wiring to stock, T-plug connector, 40A mini fuse and faston connectors to the motor, CNC trigger with zero path adjustment screw (different variants), Screw with washer for securing device in the gearbox, Black Leviathan sticker 40mm

About JeffTron

Jefftron company was founded in 2011 as a manufacturer of electronic devices for Airsoft electric guns.

20 Customer Reviews

(Write a review)

by Zeb N. on 08/16/2021
"This thing is awesome! I love how easy it is to adjust settings with my phone. The trigger response is amazing. The only thing that I wish was different is that you could make it a hair trigger, but the with the way the micro switch is set up is so that it can't have that short of a trigger pull. Nevertheless the trigger pull is still way shorter than your average trigger switch! I would highly recommend this MOSFET to anyone looking to upgrade! I will never go back to a regular trigger switch again!
by Stuart B. on 06/12/2021
"For the price, this is an amazing mosfet. After installing this into my gun the trigger response went from an extremely whiny slow m4, to basically what feels like a dsg. When paired with 13:1 gears and a high torque motor, this thing is a beast. With the small set screw that is included with the trigger it is easy to make the trigger pull next to nothing. And with the precocking turned on the trigger feels amazingly snappy. The bluetooth is also a nice and easy feature.
My only complaint (and it is my fault) is that my semi microswitch broke. I forgot that you have to file down he edges of your selector plate to prevent this. So I only have a full auto. But with the bluetooth I can program it to do semi to comply with field rules.
by THE Jaxon H. on 05/02/2021
"this mosfet is really awesome. easy to install, and very well made. the app control is the coolest feature, along with the adjustable trigger travel (if you get the included trigger which i highly recommend). I'm using it in a custom high speed APS/EMG/F1 m4, and it has barely any trigger travel. when combined with the pre cocking, and high speed setup of my gearbox, it is the ultimate anti-cheat gun. recommend over the gate titan, especially if you're on a budget.

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