sanycasa register booster fan for 4" x 12" register holes, quiet vent fan booster with intelligent thermostat, improves heating cooling, app control, 10-speeds, manhattan smart register vent, sn 4 x 12 inches satin nickel is up for auction in Home & Kitchen. The current bid is $4.50, 84% below the $28.49 MSRP, in Good Condition. This auction has ended — similar items appear in live auctions regularly.