The 5/8” Gag Open allows for two 5/8” (16mm) rods to be joined and positioned anywhere in 360 degrees. One 5/8” (16mm) pass-thru receptacle is open so that you can attach it at any point along a 5/8” (16mm) rod. The 5/8” Gag Open works perfectly for adding reinforcement components to a rigging structure.