Anti-theft and SecurityThe lock angle is smooth, not hurting the hand. Lock buckle reinforcement design, not easy to fall off, durable. Anti-collision pad at the bottom of the handle to prevent scratching the window frame. It is suitable for all UPVC doors and windows. Quality GuaranteedStrong window latch made of zinc alloy, durability and quality guaranteed, white powder coated, a good match with windows and doors. doors. Easy to use 180 degree rotation design, it can be docked at any angle. Simply twist the interference arm to lock or open the chassis. Easy to InstallClean the surface of the mounting location - Screw it in with a screwdriver - Hide with the cap to screws provided - finish to start security guarantee. Note Only use for casement windows and doors, do not adopt to sliding windows Easy to use p> Comes with fixing screws and button seals, the sash stops are easy to install with the supplied fixing screws. How many blockers should I install on my door or window? Single doors will normally have two blockers fitted one fitted to the top and one fitted to the bottom of the door. Small windows only require one sash blocker to be fitted . Patio doors and French doors will have 4 mounted on each door, two on top and two on the bottom. Door and window lock < p>Durable design Made from sturdy cast zinc with durable powder coated finish. Durable and stable What are the benefits 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 inward and outward exterior Reversible, suitable for left and right doors Can prevent the door or window from opening in the event of a break-in attempt