The Glock Gen 5 recoil spring comprises of two coaxial spring elements. These elements are assembled together with a smaller, central guiding rod and a larger tube. The assembly is similar to the recoil spring assembly used in the sub-compact models of the Glock.
Variable Spring Rate:
The result of a dual spring assembly is that the spring rate becomes variable. A single recoil spring (like gen3 Glocks) demonstrates linear damping. The variable spring demonstrates progressive damping which smooths out recoil. This dual spring assembly also deals with the stronger recoil and pressure spike of the 40 S&W calibers. Constructed of stainless steel with chrome silicon springs.
Keep your Glock in perfect working condition
Glock Engineers recommend replacing your recoil spring after 5000 cycles. This assembly will not work with the Gen2 or Gen3 or Gen4 Glocks