1-5/8″ x 3-1/4″, 12 Gauge Metal Framing Channel P1001 - Unistrut
https://unistrut.biz/products/1-5-8-metal-framing-fittings/channel-sections/p1001-framing-channel/
WEBUnistrut's P1001, often known as 12 Gauge Standard or Deep Back-to-Back Strut Channel, is commonly used for trapeze supports, seismic bracing, ceiling grids, pipe, conduit, duct and cable tray supports, racks, and other general framing. Product dimensions are 1 5/8" wide x 3 1/4" tall x 12 ga. thick, back to back.
DA: 38 PA: 70 MOZ Rank: 24