The Pentek R50 is the correct replacement cartridge for the following:
The Ametek, Pentek, US Filter R50, American Plumber W50PE Whole House Pleated Polyester water filter cartridge is designed to filter coarse sand, rust, and scale particles. Because of its high dirt-holding capacity this replacement water filter cartridge is ideal for use with well-water. Part number 155038. The American Plumber W50PE filter is the same as the Ametek, Bruner, Culligan, US Filter, Pentek R50. The R50 is also a replacement for Keystone 550 filter.
The Pentek R50 specifications:
This polyester water filter needs to be changed every 4 months.
View the Full Product Specifications for this item.