I have a set of six. It should contain bits with a radius of 1/8", 1/4", 5/16", 3/8", 7/16", 1/2". The kit does not include the numbers that correspond to the letters in the bitmap. Shaft size in inches, diameter in mm but not accurate enough. I measured the bits with calipers. It turned out that the set I got contained 1/8, 5/16, 3/16, 1/4, 3/8 and 7/16. It did not include a 1/2" radius drill bit. As another reviewer said, the bearings aren't good either.