✅SPECIAL DESIGN: Support most of the window units 9000-22000BTU. Transfer the stress and weight from the window sill to the bracket for safety, support up to 165lbs. ✅WIDELY USED：Adapts to most window styles, Compatible with 4″-15″ thick walls with window sill, and window sill should at least 2″ thick to provide enough space to mount the bracket.