Features: 
Over the door knob design for portable installation.
Large internal cavity prevents jamming, even when holding multiple keys.
Set your own combination convenience for optimal security.
Set your own 4-digit combination for keyless convenience and increased security.
Protective weather cover prevents freezing and jamming.
Molded body and vinyl coated shackle prevent scratching.

Specification:
Model Number: MH904
Material: Aluminum Alloy + Zinc Alloy
Color: Grey
Internal Space Size: 75*80*40mm/2.95*3.14*1.57in
Item Size: 160*95*45mm/6.29*3.74*1.77in
Package Size: 17*11*5cm
Package Weight: 594g/20.95oz

Package List:
1* Key Storage Lock Box 
1* User Manual