Brush Drive Turbine Complete for SteamVacs with attachment sets that manually are installed on the SteamVacs Dirty Water Tank for use. This air driven turbine/transmission drives the carpet cleaning brushes and distributes water to the brushes. manufactured to fit older units to todays Spin Scrub 50 units. Has a small sqaure reciever to accept the sqaure drive pin from the brush set.Older Models F5851, F5855, F5859 and todays F5912 and F5914. Also Commercial Spot Cleaner SteamVac.The last group of Spin-Scub 50's >2015 used a larger 6 corner drive pin so a different transmission is required (look up H-440006853) HV43191008 was the original part # for first production group. OEM Hoover. 11/22/21 dda