Product Info Catalog Hardware Builders Hardware Springs Extension Spring, 1-1/4-In. OD x 10-In. Extension Spring, 1-1/4-In. OD x 10-In. Request a Quote UPC: 38594003398 SKU: 681809 Model Number: C-339 1-1/4" OD, Extension Spring, 10" Length, .148" Wire Diameter, 6.18" Maximum Deflection, 73.7 LB Maximum Safe Load, Bulk With UPC.