Sturdy and light, free standing, cast aluminum. Both clamps(top & back) reach centerline at up to 13.5". Top bolt on each 7.5", 1 3/8" bottom bolt. 3/16" hex socket end on top bolt. Width of opening: with two swivels 4 3/8", with one swivel 5". Locking 1 1/8" nylon swivels.
