Click or scroll to zoom Tap or pinch to zoom Click or scroll to zoom Tap or pinch to zoom ULTIMATE M135 Spring - Red by ULTIMATE €13.99 SKU 18767 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart High quality spring from ULTIMATE. This is the Red M135 spring from ASG Military specification spring steel which means the best possible steel for springs. The calibration test has been carried out on 6.03 - 300mm barrel. Zero hopup with 0.20g BB's. Progressive coiling - Provides a soft start which eases stress on both mechanical and electrical parts. Closed and grinded ends - Stable straight ends minimizes side bending which reduce ROF loss. Pre-compressed which greatly reduces power loss from initial shrinkage. Black zink plating which is the only corrosion protection which does not impair spring performance. Full specification control secures exact same specification at every spring. Color coding for easy indication of individual spring grade View our entire range of ULTIMATE parts here.