Sliding T Bevel

A sliding T bevel, also known as a bevel gauge, is an adjustable gauge for setting and transferring angles.
These are really useful for woodworking and tile cutting. I use them for taking angles directly from a part to compare to a protractor.

Wikipedia Explanation: http://en.wikipedia.org/wiki/Sliding_T_bevel

Steel version on amazon for comparison: http://amzn.to/28MuIaL