Evike.com Irregular Pitch Airsoft AEG Tune-up Spring (Power: M125 400~470 FPS)

Features:

Irregular pitch spring coils: Variable tension. Reduces stress, wear and tear for your gearbox
Strength: Made out of stainless steel. Increased tension and durability. Tension lasts 50% longer than other leading brands
Compatibility: Designed for all versions of Airsoft AEG gearboxes

Spring Power Chart. (% / FPS)
FPS estimate based on average power output. Exact FPS result may vary based on alignment, installation, inner barrel, cylinder and other factors.

120% (M90) ~280~340 F.P.S.
130% (M95) ~290~370 F.P.S.
140% (M100) ~320~380 F.P.S.
150% (M110) ~330~390 F.P.S.
160% (M113) ~340~400F.P.S.
170% (M115) ~350~420 F.P.S.
190% (M120) ~360~450 F.P.S.
210% (M125) ~400~470 F.P.S.
235% (M130) ~420~500 F.P.S.
260% (M140) ~450~550 F.P.S.
300% (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.

Evike.com Airsoft AEG Tip:
Always reset your spring by firing one shot in semi-automatic before putting it away.
M120 / 190% or stronger spring upgrade may require reinforcement of other gear box internal parts.
9.6V or Stronger battery may be required to power higher than stock springs.