The Hydronix SDP-4520 Carbon Filter is the correct replacement for the following:
The Hydronix SDP-4520 20" Radial Flow Carbon Filter is a 25 micron whole house carbon filter is ideal for odor reduction and chloramine taste in Point-of-Entry Systems (POE) and other high-flow rate applications. This sediment depth cartridge should not be used with water that is microbiologically unsafe or of unknown quality without adequate disinfection before or after the system.
Hydronix SDP-4520 20" Radial Flow Carbon Filter Specifications:
The Hydronix SDP-4520 20" Radial Flow Carbon Filter fits the following compatible housing units: Hydronix HF45-20BLBK34, HF45-20BLBK34PR, HF45-20BLBK10, HF45-20BLBK10PR, HF45-20CLBK10PR, HF45-20BLBK15 and HF45-20BLBK15PR; Pentek 10" and #20 Big Blue, Big White and Big Clear Housings; Pentek 150467, 150233, 150234, 150239, 150240, 150235, 150236, 166227, 166141, 166142, 166144, 150111 and 150194 housings, along with most 20" x 4 1/2" housing units.