The Light Source Square-Coupler XL, 4", Mill

Great for hanging speakers or whatever your application needs from 4" square tube structural members. Easy installation, slide up onto tube, flip the link over, tighten the wing nut. Recessed hex pocket for 1/2" bolts. 1/2:-13tpi x 1.25" grade 8 yellow zinc plated, with 1" Belleville washer and nylock nut provided with clamp.