This Prime-Line U 9921 Adjustable Sliding Door Lock features a telescopic design that allows it to adjust to fit nearly all standard patio door openings. The lock bar is adjustable to accommodate openings from 28 inch to 48 inch Secure your door in an open position, so you can safely allow fresh air into your home. When not in use, simply swing the metal security bar up and out of the way. Unlike typical patio door patio door lock bar, this door lock stick does not require you to cut the unit down to size with a saw. You simply press in the tension release clip to extend the length or reduce the length. Constructed of aluminum with a white finish, the patio safety bar prevents doors from being forced open. Please refer to the line art drawing for dimensions and compare to your needs before purchasing.