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).