For Engelbert Schmid horns. These stainless steel screws are twice as long as the stock screws. They completely fill the interior of the stop arm so that, instead of having a thin, hollow tube, you have a solid steel shaft that runs the entire length of the stop arm and makes it much stronger. An additional benefit is that you never have to worry about a screw falling out and getting lost while changing strings. (You will have to re-tap the stop arms.)