Accessory: Mast Mount for UL-190A-B376 Antenna The ACC-A376M Mast Mount is used to install a UL-190A-B376 Antenna on a mast structure with an outside diameter of up to 38 mm (1.5"). The Mast Mount includes two U-Bolts and four 1/4"-20 screws, plus their respective nuts, to securely fasten a UL-190A-B376 antenna. Hardware is Stainless or Coated Steel.