Casement Window Air Conditioner: This Keystone vertical air conditioner fits your standard sliding and casement windows; It is rated 10,000 BTUs and best used in a room up to 450 square feet Maximum Comfort: Featuring 3 cooling modes, 3 fan speeds, 4-way adjustable air louvers and a timer; Aside from cooling, 0.9 pints of moisture from the air is removed every hour with the built-in dehumidification system Control Your Comfort: 4-way air direction control allows you to direct the air where you need it most for optimal comfort Powerful Cooling on a Budget: Our sliding window air conditioner will give your electric bill a break by using the 'Energy Saver' or 'Sleep' mode; These features automatically program your unit to use less energy Easy to Use: Designed with a removable chassis so you can install it either in a window or through an exterior wall; An adjustable window kit is included for convenient installation; Minimum window height: 21.3"; Minimum to Maximum window width: 15.5"-16.3"