CEJN 10-664-6401 Nipple 5/8 (DN16) ISO16028 FF -Press. Elim., 3/4 NPT Fem. Connection,NBR CEJN Series 664 is a Flat-Face quick-connect nipple with a built-in pressure eliminator. The nipple is according to and exceeds the demands in the ISO 16028 Standard for low- and medium-pressure hydraulic applications. The Flat-Face design minimizes spillage during connection and disconnection. The pressure eliminator allows for connection with residual/trapped pressure on the nipple side. The nipple Series 664 connects with couplings in Series 665.