Sash Jammers are designed to provide additional security for your uPVC doors and windows. They're easy to fit and easy to operate too - just a twist of the Jammer Arm will lock or release the sash. These versatile Sash Jammers can be fitted to both inward and outward opening doors and windows! We've created an easy-to-follow fitting guide, which is supplied with the jammers and will help you get started. When ordering your sash jammers, consider that a single door should have 2, double doors should have 4, small top opening window would need just 1, and larger opening windows 2.