Glider Bracket Hardware, Glider Bearing Arms, Set of 4 Stainless Steel 5/16 /6-1/2 Arms measure 6-1/2" from center hole to center hole Overall measures 8-1/8" x 1-7/16" Bearings ID is 5/16" Stainless Steel Arm with Stainless Steel Bearing Set of 4 arms