To be anal, the specific use is for measureing the gap on spark plugs as the gap on the plugs should be the same as each other and to a set gap determined by the manufacturer of the plug and engine, the wrong size plug gap will cause the engine to run at less power or efficency.
Since invention they have been put to various uses and indeed used as a run of the mill 'go' 'no-go' gauge for thin gaps, you keep sliding the feelers in untiul you find the one which fits in the gap but isnt loose or too tight to move, not often used in engineering but more fitting
They still arent much cop for normal picks though unless you get a set which has all the thicker blades in but the material isnt the best,
If you want a simular thing, use the body and cut out all the feelers and replace them with hacksaw blades, they have a hole in one end so you can get 2 picks/feelers out of one blade,
^^^^ Didn't leave many scraps for anyone else there wtf|pickproof? 
If it ain't broke.....pull it down and see how it works anyway!
