GLOCK Magazine Spring; G17, G18, G22, G31, G34, G35, G37
G17, G18, G34: 19-rd mags only (17-rd mag with 7151 floorplate & 7165 insert)
G22, G31, G35, G37 11-coil spring (must be used withTac-Lights)
Models: G17, G17L, G18, G22, G31, G34, G35, G37 (including Gen4)
Additionally, if you have a tac-light on your GLOCK and are experiencing feeding problems, this spring is recommended.
This is the extra power spring for 17 round, G17 (9mm) mags with the GLOCK +2 on them.