Extra SecurityLockable Sash Jammers are designed to provide additional security for UPVC Doors and Windows. Effectively prevent children opening windows by curious and can also stop intruders. Increase the safety of babies, pets when out of your line of sight. Strong Alloy MaterialSash Blockers are made of premium zinc alloy material,ensuring high strength and durability. Durable and not easy to wear and rust. Popular white powder coated finish, a good match with your windows and doors. Easy to UseSimple installation within minutes with accessories we provided. Simply a twist of the jammer arm will lock or release the sash locks. Especially with keys, the arm can be locked into place, more secure and reliable. Practical FittingsDesigned with a screw-reinforced anti-pinch arm, making base and the lock arm are tightly integrated and avoid loosening. Anti-wear pads can reduce friction between Jammer arm and windows. Protect your UPVC windows or door from being scratched. What You Get4 pcs sash blocker jammers with keys, 4 pcs sash packers, 4 pcs button spacers, 8 pcs fixing screws and screw cap covers. Trustworthy, low-cost and quick security solution for doors and windows inside and outside.