8kg Upgrade Spring for Mega Cycloneshock, Mega Magnus, Stampede, Nite Finder, & Dual-Strike 8kg custom fitted upgrade spring. Compatible with Mega Cycloneshock, Mega Magnus, Stampede*, Nite Finder, & Dual-Strike. Mod at your own risk! Increasing the spring tension can break or damage stock internal components of your blaster. Some blasters are extremely hard to reassemble, and we won't be able to troubleshoot problems due to user error. Blaster not included.