The Nello 18" pair of wall mounts allow for mounting directly into masonry, metal or wood for supporting antenna installations. Ideal for mounting to the wall of a building where clearance of up to eighteen inches is needed to overcome obstacles like eaves and pipes. It's made to accept 1.25" - 1.75" outer diameter masts and is popular for cellular, radio, and TV antennas. Extra support is provided by the third leg on the bottom wall mount to ensure long lasting performance.