The size and shape of the metal channel determines, for the most part, brush size and density. Although its primary function is to hold the fill material, the channel itself can be used as a mounting surface or designed to fit into shaped holders.
Six channel holders for anti-static strip brushes are available in sizes 4 (3/16" x 3/16") and 7 (5/16" x 5/16"). The channels are made from either aluminum or stainless steel.