Imagine Bio3 - Whisper Regular 4-Pack

Created by the original designers of the Whisper cartridges, these cartridges offer superior 3-stage filtration. The only cartridge currently available with a built-in biological sponge.

Fits BioSystem models 25 and 35, Whisper models C, 1, 2, 3, 20, 30, 40, & 60, Pulsar models 125, 200, & 300, and Whisper Triad models 20, 30, 40, & 60. Also fits the Top Fin 20, 30, 40, and 60 filters sold exclusively by Petsmart.