Premium key locking sash jammer for extra secure windows and doors. Strong cast zinc body and durable powder-coated finish means it'll work well and look great for years. Supplied with variety of fixings including jack nuts and screws. Additional security for windows and doors that can be quickly fitted and is easy to operate. Sash Jammers, also known as Sash Blockers offer highly effective protection against intrusion and are popular for use in offices, schools, universities and hospitals as well as housing. The underside of the Jammer Arm is 21mm from the base of the Jammer Body, so packers should be used if the offset between frame and sash is greater than 21mm. Using the Packers, the sash jammer can be used with an offset from 21mm to 30mm. Each Sash Jammer includes Key Locking Sash Jammer, Sash Packers (3mm and 6mm, for accommodating deeper offset), Button Spacers (2mm, 4mm, 6mm), 2 x Screw Covers, Sash Jammer Key, 2 x Self-Drilling Screws (no need for pilot holes on reinforced frame/sash), 2 x Universal Screws (deeper thread for non-reinforced sash or frame), and 2 x Jack Nuts (most secure option when no re-inforcement).