Made From Hdpe (High Density Polyethylene) These Bottles Are Very Lightweight And Durable Making Them Great For Backpacking. Wide Mouth Opening (63 Mm) Makes Them Easy To Fill With Ice Or To Clean. Weighs 4.4 Oz.table.productattributes, .productattributes td { border-bottom: 1px solid #ddd; border-collapse: collapse; padding: 2px; text-align: left; }