You have to pin down what brand and model bicycle you have to determine which bolt through DT shifter bosses you need to find, as the concave bushings or shifter boss bases will need to have the correct concave radius to match up to the frame's DT. Another brand that I believe have not been mentioned that uses this type of DT shifter boss mount is Vitus. They used it on their "Carbone" frames, and I think on their aluminum 979 and 992 frames too. If the frame is a Vitus, a set of the bolt through shifter, had been posted on eBay for auction on and off in the last few months.....