Designed to fit flat bottom rectangular style fuel cells with minimum dimensions of 11" long and 11" wide square. For best performance, the return fuel should be discharged near the pick-up of the HydraMat at a minimum distance of 1 inch above the mat.HydraMats with a female NPT thread do not require the use of a sealing paste or tape. Use of a sealing paste or tape could result in fuel pump failure.