Pat Cravens wrote an answer about Alpina Blazer Touring Boot on January 15, 2011
I, too, am looking for boots to fit my Trak skiis with 3 pin bindings that I have had since 1983. I did a liitle research and found that there are 2 sizes of "3-pin" boots and bindings. There are 50 mm and 75mm. The difference is the width of the tip or "bill" of the boot which rests inside the toe of the binding. The smaller (50mm) is about 1.5 inches in width, the 75 mm is about 2.5 inches. Measure the inside of your binding where the tip of the boot would rest. I found that my bindings are 75 mm. If yours are the same, these boots would fit your 3 pin skiis.