Just to be on the safe side with one of my first carved projects I purchased a "Thickness Caliper". Besides, I've always loved the look of this tool.
Obviously the caliper is pretty straight forward, but it came with this bag that has a small allen key and a small size threaded rod and I don't know how either of them is applicable. I don't want to screw this instrument up so I thought I would ask if anyone here has any experience with them. I'm attaching a picture that shows the caliper and the bag with the two "mystery items"!!!