The Antennas Direct® ClearStream® J-Mount is a 20-in. mast with a 1-in. diameter, a perfect size for the ClearStream 1MAX®, the ClearStream® MAX-V, the ClearStream® MAX-V Pro TV antennas, or any antenna 18-in. tall or less. This antenna mast is made with all-weather, powder-coated steel for optimal durability in various weather conditions and features a pivoting base that allows for installation on vertical or horizontal flat surfaces, such as a roof, fascia, deck rail, or the side of your house. Both ends of the mast can be used with the pivoting base.