Compatible: This filter is compatible with NPET WF020TP transparent/semi-blue/semi/white pet fountain.
Material: Food grade Resin + Activated carbon
Function: Filter pet hair and most other impurities, remove odor.
Size(L*W*H): 4.5 x 1.1 x 0.5 inches (single filter)
Specification: 4pcs per selling box
Suggestions: a) Rinse the filter with water about 10 mins before use
b) Replace the filter every 4 to 6 weeks, it depends on actual filter status.