Wood base, o/a dim. 7 ft 9 in. Lg, 15 in. W, w/two single flangedwheels, 3 in. Tread w, independent shafts and bearings, 5 ft 3-1/8 in.Between flanges, w/other necessary hardware to make a complete unit, designed for end launching of p-series pontoon strings, navfac dwg no.889752, mark no. Jt-4