Hello, my name is Steven. I am the CEO of Daewon Industries. Welcome to our site! We offer micro drill bit packs in many sizes and quantities. From single-size packs to mixed packs to larger quantity packs, we have what you are looking for. All the bits are Japanese made tungsten carbide. They come in sealed protective plastic cases and are shipped out within 24 hours of the order, Monday thru Friday. These bits have a long list of uses, including jewelry making, installation, modeling, woodworking and 3D printer nozzle cleaning to name a few.