I enjoy working with wood. I also do some CNC wood carving which they are excellent at. This is a set of 5 identical tungsten carbide (TC) carbide bits in individual cases with 1/8" shank and spiral countersunk cutter. They can be used with any high speed 1/8" shank router tool such as the 3018-Pro CNC router or the Foredom handheld rotary tool with extreme care. Being hard TCs, they are somewhat brittle, although should wear well if used in materials such as wood or plastic. I would not recommend them for use with metal. I appreciate that the bits are individually labeled and encased to limit damage from hitting each other. Careful examination with magnification tells me these are sharp bits with no defects. I recommend this HQMaster shop. I hope you found the information and my review helpful.