Snap-on Float Valve Mount
This is just for the mount. If you are instead looking for the mount and top-off float valve combo:
Float valve bracket mount fits only Aqueon rimmed aquariums. The type found at Petco for $1/gal.
No additional hardware needed! It is designed to slide in on the black rim and snaps securely on the rim. Mounts the float to mount 1.25 inches above the rim. Float valve water level is adjustable.
Made with high quality ABS plastic