Anti-theft and SecurityThe locking angle is smooth, not hurting the hand. Locking buckle reinforcement design, not easy to fall off, durable. Anti-collision pad at the bottom of the handle to avoid scratching the window frame. It is suitable for all UPVC windows and doors. Guaranteed QualityStrong window latch made of zinc alloy, durability and quality guaranteed, white powder coated, a good match with windows and doors. doors. Easy to use180 degree rotation design, it can be docked at any angle. Just twist the interference arm to lock or open the chassis. Easy to InstallClean the surface of the mounting location - Screw it with a screwdriver - Hide with the cap to screws provided - finish to start safety guarantee. Note Only use for casement windows and doors, do not adopt for sliding windows Easy to use Comes complete with fixing screws and button gaskets, the sash stops are easy to install with the supplied fixing screws. How many stoppers should I install on my door or window? Single doors will normally have two blockers fitted one mounted at the top and one mounted at the bottom of the door. Small windows only require one sash blocker to fit . Terrace doors and French doors will have 4 fitted to each door, two at the top and two at the bottom. Door and window lock > Durable design Made from heavy duty die-cast zinc with durable powder coated finish. Durable and stable What are the advantages of the Sash Jammer? Door jammers are a cheap way to improve the security of your uPVC door or window Easy to install Fits most types of doors and windows Fits doors and windows that open inwards and outwards exterior Reversible, suitable for left and right doors Can prevent the door or window from opening in the event of a break-in