Perun Lightning V2 (rear wired) magnifier Additional gearbox features include a

Additional gearbox features include a modular spring guide system that will allow the spring to be changed without completely disassembling the gearbox

7mm is for 11mm outer spring diameter

Sling Mounts: Rear Integral push-button QD swivel sling mount accommodates up to 1

it may be compatible with other airsoft guns

and improved performance

Perun Lightning V2 (rear wired) magnifier Additional gearbox features include aPerun V2 Lightning replaces the mechanical contacts in your airsoft replica or gel blaster and introduces a wide range of useful features. Optical and magnetic sensors eliminate moving parts entirely, providing exceptional reliability and flexibilityworking with almost any combination of gearbox shells, triggers, selector plates, and sector gears. Adaptive trigger control lets you adjust from a very short to a long trigger travel, even in the field,