Use the Pet Gate Extension Kit – 21.75 inches with three pet gates available on this website. The gates are Stairway Special Pet Gate – Outdoors (model 52250), Stairway Special Gate – Indoors (model SS-30), and the Auto Lock Attached Pet Gate (model MG-15/B). All sold separately. Use this extension with one of these gates for openings 40 1/2 inches to 61 1/2 inches. The weight is 7 pounds.