London Line from Ingersoll is designed for "ultimate security" and to exceed British Standard BS3621:2004. The mortice lock features a 20mm single throw, drill resistent Hook Bolt and fully enclosed tamper proof case. The lock is supplied with the Mul-T-Lock interactive Euro Profile Double Cylinder. Security features include the anti jemmy attack, boxed locking plate and long plate security escutcheons that also enhances appearance by masking any previous lock preparations. Ingersoll London Line mortice hook bolt locks are available in a chrome or brass finish. Use with Ingersoll London Line Nightlatch.