Nerf mod Kronos Spring (Strong-prime) 135FPS average (NEW) - Out of Darts
Kronos 3.7" K26 Spring with squared ends
Nerf mod Kronos Spring (Strong-prime) 135FPS average (NEW) - Out of Darts
Kronos 3.7" K26 Spring with squared ends

Rival Kronos Spring (135+ FPS) Strong Prime

Regular price $5.00 Sale

This custom Rival Kronos spring has been manufacture and 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 built and tested to fit the Rival Kronos blaster.

• Medium difficulty on installation
• Both ends flat/squared
• Average 135-140 FPS

• Cut-to-Length Compression Spring,
• Material: Made in the USA of USA spring-tempered steel
• Dimensions: 3.7" Long, flat on both ends


Customer Reviews

Based on 111 reviews
Brody Bingham
It is just so fun to shoot

This spring was super easy to install, and shoots fast, hard, and makes a loud pop when fired. The pull-back is hard but is easier if you use to fingers to slide it back from the sides. It is definitely worth it and I am thinking about getting more for another Kronos and even other Rival blasters like the takedown and roundhouse. I just get so excited every time I fire it it just works terrifically. Because of the enhanced speed, it sometimes curves a bit but is not too much of an issue.

Jayden A
Great mod

Quick and easy to install, took about 15 minutes. Pretty hard to prime but shoots hard. Left a nice mark on my back after getting shot with it. Super fun!


While it's a k25 spring, it made a HUGE upgrade from a standard k26 in my rival finisher. Normally had to roll headshot for those people that wouldn't acknowledge their "hits". This makes even the softer nerf rounds a good honesty checker.
I'll be grabbing some more in the future.

Sam Maxwell
Very Pleased with the Spring!

I bought two of these and they both worked excellently! The prime is strong as advertised as it has to be to shoot so hard, but for any older teens it is well worth it. At this price it's a must have upgrade.


Works exactly as advertised. Out performs nearly every other blaster in some of the dormitory nerf wars. Turns a blaster that's good for ganking and plays around cover into the equivalent of a hand-cannon. Gotta have a strong grip for use over a few hours- consider the slightly lighter spring otherwise.