Matrix Regular Pitch Airsoft AEG Upgrade Spring

Features Irregular Pitch Spring Coils: Variable Tension. Reduces stress, wear and tear for your Gearbox Made out of Stainless Steel. Increased tension and durability. Tension lasts 50% longer than other leading brands Designed for all version Airsoft AEG gearboxes   (M85) ~270~310 F.P.S. (M90) ~280~340 F.P.S. (M95) ~290~370 F.P.S. (M100) ~320~380 F.P.S. (M110) ~330~390 F.P.S. (M113) ~340~400F.P.S. (M115) ~350~420 F.P.S. (M120) ~360~450 F.P.S. (M125) ~400~470 F.P.S. (M130) ~420~500 F.P.S. (M140) ~450~550 F.P.S. (M150) ~480~600 F.P.S. M160 : ~530+ 20 F.P.S. M170 : ~560+ 20 F.P.S. M180 : ~595+ 20 F.P.S. M190 : ~625 + 20 F.P.S.