Leviathan - V2 optical is one of the most advanced control units on the market. It combines optical and microswitch sensors for better control and durability. Integrated wireless communication for quick setup via smartphone ( iOS or Android ). The trigger switch has a pressure of only 0.13 mm to achieve the perfect hair trigger mode. The unique Real Trigger System (RFTS) withintegrated spring simulates the resistance of the trigger as in a real weapon . Adds secondary resistance with trigger reset after firing. The RFTS was designed by a professional rifleman for a more realistic shooting feel.