Adjustable width 22-1/2" to 36". set screws secure at desired width. Stainless steel torsion spring closes the gate automatically. Spring is tension adjustable, and reversible. Meets OSHA 1910.23a requirements. Powder coated red finish (except spring). Outside tubing 1.37" OD x 12 gauge wall. Mounting channel is 2" with easy mount kit to mount directly on your existing hand rail. Two bolt together clamps hold unit securely to hand rail. No drilling required.