Cooper B-Line Rectangular post base is made of malleable iron with electro-plated zinc finish for added durability and corrosion resistance. It measures 7 in. x 2-1/16 in. x 4 Inch x 1/4 in. Base is ideal for use with 3/8 in. channel in any industrial support application. It features two 3/4 ib. holes for channel mounting. Base provides channel position at the center for convenience.