... 1) AS-568, PG, DIN, BS standard and non-standard Silicone O-Rings 2) Various colors available ... PU o ring:Product and sell all kinds of O ring,Y ring ... U ring,etc.1) AS-568, PG standard and non-standard Silicone O-rings 2) Various colors ... the ISO9001, ISO14001 and NSF-61 system 5) Excellent chemical and physical property6) Customers' designs and specifications are accepted7) ...