This is the Flow indicator assembly for the Bissell ProHeat deep cleaner model 1697.  This is the part on the top of the base of the cleaner, which spins when water is flowing through the unit without obstruction, and stops spinning if there's an issue that needs to be checked.   The assembly includes the red spinner, the white base, and the clear plastic dome that covers the assembly. 

Genuine Bissell part number 5556503, or 010-7635.