Product Info Catalog Hardware Builders Hardware Springs Extension Springs, 1/2-In. OD x 4-1/2-In., 2-Pack Extension Springs, 1/2-In. OD x 4-1/2-In., 2-Pack Request a Quote UPC: 38594002216 SKU: 681403 Model Number: C-221 2 Pack, 1/2" OD, Extension Spring, 4-1/2" Length, .062" Wire Diameter, 2.93" Maximum Deflection, 15.9 LB Maximum Safe Load, Polybag.