vee block using qulity tool steel manufacturing, we are one of the biggest maufacturer in china I-V-frame using quality tool steel manufacturing, II-type V-rack HT200 materials used, I II III type aircraft generally paired supply, IV-type V-rack in general sets of supply, each five pairs of, angles were .60 degrees , 72 degrees, 90 degrees, 108 degrees, 120 degrees