Q. Which lock is best for sliding window?

Lion Locks Sliding Door Lock would be the best for window locks. The Lion Lock has two thumbscrews for a firm hold and a rubber grip that will not let go of the door's track. The door can't be pulled back far enough to allow someone to sneak in or out. There is one major fault in the Lion Lock's design according to experts. Anyone trying to break in will be thwarted by this device as it prevents the sliding door from opening but it can be quickly undone from the inside. The thumbscrews may be loosened and the door opened by children teenagers or even some adults.