3/16" SE shape carbide burr, single cut, oval shape.
A rotary burr for deburring, weld dressing, shaping and blending in a die grinder or air tool. This one cuts 3/16" diameter with 5/16" of cut on a 1/4" shank, 2" overall.
The single cut has one row of flutes, which produces long chips and cuts fast — it suits steel and harder ferrous metals and leaves a rougher surface.