Tetra Replacement Suction Cups - Not for Whisper Suction Cups for all Tetra Foam Filters, CO2 Systems, Luft Diffusers NOT for heaters or Whisper internal filter models 10i thru 40i. Will work on Whisper 3i item# 25846 FEMALE END, MOUNTS ON POST DOES NOT fit filters with hole to pop suction cup end through