Each set includes 5 complete tool kits with 20 inserts per kit "10 each of short and long" for a total of 100 inserts. Thread Sizes= 1/4-28, 5/16-24, 3/8-24, 7/16-20, 1/2-20 Master kit p/n 0020 (1/4-28x.380 / 1/4-28x.500), (5/16-24x.450 / 5/16-24x.620), (3/8-24x.520 / 3/8-24x.750), (7/16-20x.620 / 7/16-20x.870), (1/2-20x.650 / 1/2-20x1.00)