The Master Lock 540 Wall Mounted Key Lock Box enables the safe storage of house keys or even cash. Door keys can be safely left for children to get in after school, for an elderly family member you need to visit on a regular basis, or for just storing keys safely. The 5401 is packed with high quality features and it is fitted with an easy-to-set 4 digit combination security lock with hundreds of multiple code options. A tough metal body provides the ability to store larger items and not just keys. Can be used both inside and outside the home, office, worksite or anywhere that restricted or safe access is required. All Master Lock products with a locking mechanism have a Lifetime Warranty against mechanical failure. 5401/5401CRM: Standard Key Box: Holds Upto 3 Keys. 5403E Large Key Box: Holds Upto 5 Keys.Mater Lock 5401E Large Wall Mounted Key Lock Box has the following specification: External Dimensions: 105 x 146 x 51mm.Internal Dimensions: 79 x 117 x 42mm.Colour: Grey/Black.