SR25 Retro Arms SiCr spring with a progressive irregular coil M110

SR25 Retro Arms SiCr Spring with Progressive Irregular Coil M110

Main spring made of steel with chromium and silicon alloy, for Long type gearboxes.
The progressive coil facilitates the winding of the spring without depriving it of power.

Spring dimensions:
Inner: 11.3 mm
Outer: 14.5 mm
Length: 200 mm