The American Plumber W38-OR is an o-ring for the following water filtration systems and housings:
The American Plumber W38-OR O-Ring is a replacement o-ring for all American Plumber 3/8 inch I/O Filter Housings, WLCS-500 Undersink System, and WRO-3167 Reverse Osmosis System. American Plumber Part 152031. Fits 3/8 inch Slim Line Housings.
This O-ring is also known as the Buna-N #237 and 237-7470-10. Part number 151121 by Pentek, Ametek, Pentair. This o-ring also replaces the Pentek o-ring 158648.
The American Plumber W38-OR O-Ring, 151121 also has these part numbers: