DMM Wallnuts are a benchmark to which all forms of nut protection are compared. With their 3 Sigma rating, Wallnuts are hot forged from aluminum 7075 T6 or 6082 T6 depending on size and their galvanized steel cables are swaged using an advanced system with extra long ferrules for maximum strength and security. Wallnuts are designed to cover a size range of placements from 2 mm 32 mm, and each size overlaps with the next when turned sideways for ultimate user friendliness. Note that this item of climbing safety equipment is non returnable. Please call us toll free at 877 236 8428 or e mail bentgatebentgate.com with any questions.