【4pcs Window Security】Comes with fixing screws, cover caps, sash packers, button spacers, these window blockers are perfect for adding security to your home. 【Key Supplied】The locking arm can also be locked with the supplied key and can be used on UPVC windows or doors. 【Easy Operation】These door locks are easy to install, a simple twist of the blocker arm blocker or will release the belt. 【Durable Material】These window blockers are made of high quality aluminum alloy, these child safety windows are durable to use. 【Fine White Decoration】White powder coat finish, good match with your windows and doors.