The Worker MOD spring is specially design for Swift blaster, this spring built by a 1.7mm wire that enpower your blaster.
Buffer pad for the plunger included to reduce damage when "dry" fire, it is optional but please be careful on use of strong spring.
Worker MOD 1.8mm Wire Spring Coil Upgrade Kit for Swift Blaster Toy
Size (LxDia, mm): 350 x 11
Weight (g): 60
Material: Music Wire
Fomation: Coil forming
Packing Size (LxWxH, mm): 360 x 20 x 20