We've made this custom Spring out of Rocket Wire, the best aerospace material we could find, for the longest continuous use possible.
We also go to the extra steps of peening the surface, which is a way to polish the surface so there are no minute cracks that can grow over time and contribute to Spring failure, and we lightly oil them to prevent surface rust that also shortens duty cycle.
We recommend that you use a liberal amount of Marine Grease (what we use at the factory) or a high quality bicycle bearing grease for quiet and long-lasting action.
-1.25" long x 5/8" OD.
It's easy to install, see C7 TECH SPECS for detailed instructions.