This set of solid aluminum jigs, or Leatherworking Squares, can be used for marking, cutting, pattern replication, perfect stamp alignment, and so much more.
Included in the set:
-One 8” x 1” solid aluminum bar
-One 1/2” x 1/4” solid aluminum square with 4” arms
-One 1/2” x 1/2” solid aluminum square with 4” arms
Here's a great video from one of the creators that explains just why you need this and how to use it.