Product Info Catalog Hardware Builders Hardware Springs Extension Springs, 9/16-In. OD x 6-In., 2-Pack Extension Springs, 9/16-In. OD x 6-In., 2-Pack Request a Quote UPC: 38594002315 SKU: 681437 Model Number: C-231 2 Pack, 9/16" OD, Extension Spring, 6" Length, .072" Wire Diameter, 3.61" Maximum Deflection, 21.1 LB Maximum Safe Load, Polybag.