This face spanner or compass wrench is a must-have for scuba technicians. It is a general hand tool that will find lots of uses in scuba service work. 

There are 6 different pin sizes (1.7 mm, 2.3 mm, 2.8 mm, 3.3 mm, 3.9 mm, and 4.2 mm) available for use with this modular version of face spanner. The pair of pins are NOT included with the spanner and must be purchased seperately here. This will enable technicians to mix and match according to their needs and preferences.

Some examples are:

The body is made from steel.