This is a set of (3) 1mm diamond coated TWIST drill bits. . Recommended for drilling holes in sea glass,beach stones, stained glass These diamond twist coated diamond drill bits are very popular with jewelry artist & designers 1mm is a popular size, often used by toy model makers as well as jewelry artist. FREE with purchase are some tips & suggestions that I wrote that you may find helpful. " Drilling Holes in Sea Glass & Beach Stones"
. These diamond bits can be used in any Dremel type rotary tool. mailed frim for quick delivery