Airsoft Mutation Power Boost Spring Guide Spacers (10.2mm ID, 15.0mm OD, 5-pack)

Spring Guide Spacer (Pack of 5) Very handy spacers for fine-tuning power output. - Made with USA prime resin Polyamide filament - Highly Ductile filament - Shock Absorption & Noise Reduction - Increases FPS (~5 to 15 fps per ring) As a general rule, do not exceed 3 spacers. At that point, using a stronger spring is recommended. Inner & Outer Diameter : - 10.2mm & 15.0 mm PLEASE measure your spring guide to be certain of the correct sizing. Other sizes are available.