14 Gauge Strut Channel with Holes PS 500 H has round holes on the back side for use with 1/2" threaded rod and fasteners (or smaller diameters with use of flat washers). These holes can eliminate the need for field drilling when installing a trapeze support, anchoring the channel to a surface, or for many other applications. This channel is commonly used for trapeze supports, seismic bracing, and anchoring to floors, ceilings and walls. This is a great product for certain seismic bracing applications where slots are not allowed. Product dimensions are 1 5/8" wide x 13/16" tall x 14 ga. thick; with round holes on one side. The holes are 9/16" in diameter and 1 7/8" on center. The hole diameters and spacing match Unistruts general fittings so that nearly all our fittings can be attached through these holes.