NOTES FROM LUKE: This precut Rival Mercury spring cut from the K25 has been tested by the OOD team as a perfect upgrade mod for your blaster. This mod is not for young kids! You'll need fairly strong hands to prime this spring. This spring has been custom cut and tested to fit the Rival Kronos blaster.
FEATURES: -Medium difficulty on installation -One end will be flat/squared, the other will be a raw cut. -Average 125 FPS
SPECS: -Cut-to-Length Compression Spring, -Spring-Tempered Steel -Made in the USA of USA steel -3.7" Long, hand cut, flat on one end.