Allstar ALL50823 Aluminum Cap for -6AN 9/16-18 Thread, (Pack of 20) Cap fits size -6an and 9/16-18 thread and is made from high-quality aluminum This cap plug is a must for keeping debris out of lines and hoses. Ideal for keeping internal components of dry sump pumps, fuel pumps, pressure regulators, etc. Clean during storage Cap fits 37 degree flared fittings and straight threaded ports Sold as one set of 20 pieces Backed by a 90-day limited factory warranty