8.5" Trampoline Springs-Quantity of 12 Zinc coated. 8.5" long from hook end to hook end when recoiled tightly, at rest, off of the trampoline. SPRING LENGTH: TAKE A SPRING OFF THE TRAMPOLINE & MEASURE IT; INCLUDING THE HOOKS, TO DETERMINE THE CORRECT LENGTH. (The spring coils must be fully recoiled to obtain the proper length.) FITS ROUND AND "SOME" RECTANGLE TRAMPOLINES.