... UP,UHCP, UWPP,WP,WC and so on.Pull plug is just a small range of our products. ... The products presented in this page is made of EPDM, which is superior at oxidation resistance, Ozone resistance ... end through into the hole. As the plug is pulled the large diameter stretches and becomes smaller, ... is in position and the plug is released, it forms a tight seal on the hole. The plug is removed by pulling on ...