These are the mechanical / Chemical Filter Cartridges for our line of Hang-On Back (HOB) SUNSUN Filters.
The HBL-301 and HBL-701 Share the same cartridge, The HBL-301 takes one Cartridge at a time while the HBL-701 Takes 2 Cartridges.
Replacement Cartridge - HBL-301
C$1.00Price