Sign Holder Clamp for ROUND, Square or Rectangular Tubing W/ 3/8" Fitting

Amazing clamp design works with different hang rail tubing sizes. Eliminates need for using different style clamps in the same retail setting. Designed to fit 1" square hang rail tubing, up to 1" diameter round hang rail tubing, and the 1/2" x 1-1/2" rectangular hang rail tubing. 3/8" threaded fitting is for threaded stems to tightly screw into. Easily secures to the hang rail tubing by tightening the thumbscrew.