Product Info Catalog Hardware Builders Hardware Springs Extension Spring, 3/4-In. OD x 6-1/2-In. Extension Spring, 3/4-In. OD x 6-1/2-In. Request a Quote UPC: 38594002773 SKU: 681601 Model Number: C-277 3/4" OD, Extension Spring, 6-1/2" Length, .091" Wire Diameter, 4.2" Maximum Deflection, 31.3 LB Maximum Safe Load, Bulk With UPC.