Matco-Norca’s 759PLF features leak-prior-to-press technology. This design incorporates a special EPDM O-ring that allows water or air past the sealing element of any un-pressed connection. Manufactured in ISO 9002-approved factories and available in sizes 1/2" up to 4", the ball valves come with one O-ring and are compliant with UPC, AB1953, NSF-61 and NSF-372 standards. Matco-Norca.