Product Info Catalog Hardware Builders Hardware Springs Extension Springs, 9/16-In. OD x 2-7/8-In., 2-Pack Extension Springs, 9/16-In. OD x 2-7/8-In., 2-Pack Request a Quote UPC: 38594001790 SKU: 681288 Model Number: C-179 2 Pack, 9/16" OD, Extension Spring, 2-7/8" Length, .072" Wire Diameter, 1.48" Maximum Deflection, 21.1 LB Maximum Safe Load, Polybag.