This tube is more flexible than EPDM Formula, though not highly resistant to the efects of ozone and ultraviolet light. Highest quality 60 durometer natural rubber. Inside diameter 1/4″ (or 3/16″) ± 1/64″; outside diameter 9/16″ ± 1/32″; maximum specific gravity 1.20; tested accoridng to ASTM D 412 with minimum tensile strength of 2500 psi and minimum elongation of 400%. After elongation, not over 10% increase in length. After exposure to minus 10 F, tube will bend around a 11/4″ outisde diameter mandrel without cracking. After exposure to plus 175 F for 5 hours, tube, when depressed, will return to orignal state upon being released. Inside of tube is clean, smooth and free from foreign material. Lengths of 100′ or 120′ packed 3 lenths per box. Sold in box quantities. In stock.