This is Ona Odor Stop, it is designed for 4 inch ducting and has a female threaded cap on it to fit quarts of Ona deodorizing gel, it has a manual speed control. This was ordered for a customer who never came and got it and is on clearance , its brand new /never used and does not have a box, it came in a plain brown box with no instructions and all sales are final / no returns. It is priced lower than used ones on ebay!!