This the Wixey Digital Angle Gauge, a small digital angle gauge – really no more and no less than what it says on the box.
Specification:
- Resolution: 0.1 degree
- Range: +/- 150 degrees
- Repeatability: +/- 0.1 degrees
- Size: 2″ x 2″ x 1.3″
- Battery: CR2032
In use you switch it on, place on the reference surface, press the zero button and the meter will then show zero degrees.
You then move the meter onto the item for which you want to measure the surface of (relative to the reference surface) and read the angle. 
When I want to set up something in the vice on the milling machine I place the angle gauge on the table and zero the gauge before moving the gauge to the part in the vice. I then recheck the zero by putting the gauge back onto the table at another location just to ensure I have the correct reference. This feels a little over the top at first, but gives me piece of mind as they say: “measure twice, cut once”.
As you can see in the above image there are three permanent magnets fixed in the base so that you can attach the angle meter to items such as circular saw blades. These magnets are great for certain applications, but they tend to attract filings and this can disrupt how the angle gauge sits on a surface. This means you will need to clean the bottom of the gauge before using it.
Price: approx £22.50 from machine-dro.co.uk
Conclusion
The Wixey Digital angle gauge is a great item for setting up saw blades, wing dihedral, engine thrust lines etc. I use mine a lot for setting up items in the milling machine vice. The only issue is you will need to remove the battery if you only use it now and again as it will drain the battery even when it is apparently off.
Using a Mobile Phone as an angle gauge – we compared the Wixey angle gauge to a mobile phone. Both being measured against a sine bar as the defacto standard.
The mobile phone is as good as this angle gauge, the only issue is it doesn’t have a flat magnetic base. So not as easy to use.