Watch Case Opener
Extremely popular water-proof watch case opener  - complete with 12 pins/keys to suit round, square, toothed and and flat backs. 
This type of tool will open a large majority of watch backs that are screw fitting. 
Maximum jaw opening - 45mm
The standard tool only opens to 32mm.
Adjusts easily to open most screw back type cases.
Knurled handle for easy grip.
Adjustable thumb wheel