NOTES FROM LUKE: This precut Rival Jupiter spring from the K25 offers increased accuracy and speed at roughly 135FPS compared to the stock spring at 92FPS. This mod is not for young kids, you'll need fairly strong hands to prime this spring. This K25 Easy-Prime spring has been custom cut and tested to fit the Rival Jupiter blaster.
FEATURES: -Easy to Medium difficulty on installation -One end will be flat/squared, the other will be a raw cut. -Average 135 FPS
SPECS: -Cut-to-Length Compression Spring, -Spring-Tempered Steel -Made in the USA of USA steel -About 122-124mm Long (About 11 coils), hand cut, flat on one end.