1) Material: EPDM, nature rubber, SBR 2) Sizes: 10", 15", 21", 31", 40" 3) North American standard 10" 55g/pcs 15" 80g/pcs 21" 95g/pcs 31" 138g/pcs 41" 182g/pcs MOQ: 5000pcs50pcs for a carton boxes. 60boxes in a pallets.Very good quality, 100% EPDM rubber tie down, also Natural rubber. rubber tarp strap