Set consisting of:
2x Small White Spacers
2x Medium Spacers in Black
2x High Spacers in Red
 
They allow to gradually increase the compression of the firing pin spring by increasing its percussion on the primer.
 
Increases spring usage life by more than 100%
 
The kit offers 3 different compression settings.
 
Compatible for all Glock series Gen 3 - Gen 4 - Gen 5