Smart Shophar Inter Lock are designed to enhance door look and high grade of security . This lock has vertically interlocking deadbolts that are made from tough and high-grade Aluminium alloy that provides resistance against prying open or jimmying it. Due to the powder-coated finish this lock is scratch resistant too and looks new even after years of use. This lock only operates with a key from outside and with a knob from inside. You can use it on main doors in residential and commercial establishments, horizontal and vertical doors, balconies, single or double shutter doors, wooden doors, sliding doors and steel doors. If you doubt the genuineness of the brand, you will be glad to know that the manufacturers of the brand give you a warranty of 2 years on the product. You will never regret buying this home improvement product.