Finest quality coil springs, controlled-tension wound for smooth operation without binding under compression. “Over-Pin” springs are designed to function over gun pins and plungers.“OVER-PIN” KITS - 12 Coil Springs, 7 sizes, wound and sized to operate without binding over pins from 3⁄32" (2.4mm) to 3⁄16" (4.7mm). 12" long (30.5cm). Kit #1, OD-12; Light duty. Kit #2, OD-12; Heavy duty.
Big Book Catalog, Issue:69, Page:383
SPECS: High tensile spring wire. 12" (30.5cm) long.