If you want to use an aftermarket spring for your Glock, are you tired of being forced to use a spring of a different design that requires a special guide rod.
ISMI recoil springs for Glock pistols are wound from flat wire so they are a direct replacement for your factory supplied springs. Manufactured to ISO 9002 quality control standards; we use aerospace spec materials and then after winding the spring are fully processed for maximum durability and consistency. As part of the design parameters, we were careful to maintain proper required spring rates for reliability.