Spring SP140 for AEG from Guarder. The spring is the part that has the greatest influence on the muzzle velocity in the gun. It is compressed by the piston and when released, pushes it back forward in the cylinder. It is the most common and one of the cheapest upgrades. However, its use can have destructive effects if the other parts of the mechabox do not match its power.

Weight: 25g

Spring type/spring force: SP140