Not compatible with the Waterpik Classic Water Flosser (WP 60/65/72), Whitening (WF-05, WF-06), Sidekick (WF-04), Sonic Fusion (SF-01, SF-02, SF-03, SF-04), or Cordless (WP 360). Compatible with most waterpik models, such as Aquarius, Complete Care, Cordless, For Kids, ION, Nano, Ortho Care, Radiance, Traveler, Ultra.