Sash window locks are designed to operate in a addition to the fastener. Some types of sash window lock allow the window to be locked open, which is desirable during hot weather. SDS sash stops provide a secure window lock in a range of finishes.
Casement window locks are designed to operate in addition to casement fasteners and stays. Window locks are either surface fixed or concealed within the window. All window locks have a removeable key.