SeaLux Stainless Steel Heavy Duty Telescoping Hatch/Window Adjuster and Stay Support - 13" to 22" for Boat, RV Made of mirror polished stainless steel, telescopic version with locking on each position by rotation the black conical point knob, Adjuster glides easily to any length between 12-7/8" and 22-1/4". Can be easily secured position with the positive locking mechanism. Commonly used by Triton Boats and Bayliner Trophy Boats. This tubular window adjusters allow windows to remain open to ventilate areas as needed. Stainless adjuster bracket features mounts that swivel and rotate within their bracket and a black twist knob for easy lock and release.