NYLON RAIL MOUNT FOR 7/8″ TO 1″ RAILING – 1″-14 THREAD – WITH CABLE SLOT FOR EASY PASSAGE OF RG-8X AND RG-58 COAX CABLES – BLISTER PACKED UV resistant reinforced nylon rail swivel mount, design with handle locking. Special cable slot for easy passage of RG-8X and RG-58 coax cable. Built-in coax cable feed-thru. Easy installation on vertical or horizontal rails from 7/8” (22 mm) to 1” (25 mm). Standard 1”x14 thread.