M4A1 GEN9/GEN10/GEN11 UPGRADED ALLOY TAIL / SPRING RETAINER + BEARING KIT PERFECT FIT : BEASTPRO UPGRADE

  • Sale
  • $8.00
  • Regular price $14.00


They allow the spring to spin increasing RPS.

You are buying:

M4A1 GEN9/GEN10/GEN11 UPGRADED ALLOY TAIL / SPRING RETAINER + BEARING KIT PERFECT FIT : BEASTPRO UPGRADE