MULTIPLE APPLICATIONS: This Double Mast Clamp is ideal for mounting larger antennas to masts, or one pole to another. | Dimension: As shown in the picture, the diameter range of round pipe is 1 - 1.8", U bolts(2.1 " in distance, 5.7 " in length) to give a stronger install for ensuring the pole not slip down. | Material: Zinc-Plated Steel with anti-rust coating finish, revent rusting in outdoor rainwater. | Wide application: This mast mounting clamp is designed to support most WiFi, Yagi, TV antennas, Ham CB antenna, Helium Miner Lora antenna, flag post, fishing rods, patio umbrella, parasols. | Package List: 2 Sets mast