AR-House Extra-thick Door Chain Lock-- Sus304 Stainless Steel Casting Door Security Chain Guard, Heavy Duty Latch Lock for Inside Door, Brushed Nickel Finish (Deluxe Extra-Thick:3 mm) 1. Manufactured from SUS-304 Stainless Steel die-cast;With truly excellent Brushed Nickel finish--- aesthetically pleasing appearance which is peculiar to SUS-304#SS Door Chain Lock 2. Extra-thick: 3 mm , Heavy Duty Chain Latch for Inside Door, 100% durable. 3. Lock length=13 cm (about a 4.5" Phone length), width=3.5cm, height=0.8cm; Chain length=14cm 4. Security Guard-- Easy to install and operate; Can not be unlocked from the outside, Unlocks easily from the inside 5. Mounting hardware included: 1 door chain lock with mounting screws.