Both C2 and C3 brush heads are compatible with the majority of Philips Sonicare electric-powered toothbrushes. The Sonicare C2 and C3 work with nearly all click on Philips Sonicare electric toothbrush handles. The only exception is the Sonicare battery powered and Essence series that have screw-on brush heads. Changing your Sonicare brush head is painless and quick, because of its click on capability.
@seespotbark@thismyusername best sale at Costco was 8 C3 heads for $49.99 I believe (currently 64.99). I literally just bought them but I’m tempted for this deal to stockpile a bit, as the price is pretty good.