Product Description Specifications: Manufacturer: Lancer Tactical Product Construction: Stainless Steel Compatibility: Most Airsoft AEG Gearboxes Estimated muzzle velocity output of 290 - 310 FPS Features: Linear pitch coils make them optimal for high-torque motors Durable stainless steel construction Universally compatible with most airsoft AEG gearboxes WARNING: Cancer and Reproductive Harm – www.P65Warnings.ca.gov/product Customer Reviews