- Upgrade Spring for the Nerf Rival Kronos and Mercury
- 135-140 FPS perfomance
- Easy to install
Blasters & Shells
Games & Sports
Average delivery time: 2-5 days
This upgrade spring for the Kronos is a custom made spring designed by Out Of Darts. You can expect about 135-140 FPS performance after installing. It makes the prime heavy, so not suited for kids. A T-pull handle will make the prime a lot easier.