Set of 3 in-DEXABLE joiner's combination squares from Blue Spruce Toolworks. Includes Rack-Its (mounting system).  These are unique combination squares in that one side is 90 degrees, and the other side is a common dovetail ratio. The blades and heads can be intermixed. Installed the Rack-Its in the wall and had the squares stored there and only used a few times. These are great squares, they adjust easily and lock down solidly. The in-DEXABLE feature makes them easy to set at certain points (inch marks for example).

There are 3 separate squares, each with their own Rack-it mount. 
4" - 1:6 dovetail ratio