Wolff 18 LB. WOLFF VARIABLE POWER SPRING FOR COLT COMMANDER 42518

Variable rate springs function correctly with a wider range of loads than fixed rate springs can. Rate increases as spring is compressed; gives greater protection against frame battering, more consistent lockup and improved feeding, while allowing eas­ier manual cycling of the action. All springs are variable power. 18 lb. spring is factory ­standard; includes extra power firing pin spring. Manufacturer Part Number: 42518