Standard (coarse) Ruby Carver in a small ball nose shape with ruby crystals firmly bonded to a metal frame. Coarser grit Rubies provide faster material removal over fine grit but leave a slightly rougher finish. They are especially good on wood. 5.5mm head dia. x 10mm head length, 2.35mm shank (3/32"). Made in Switzerland. 35,000 RPM Max Speed.