3/4" body 60° countersink, 1 flutes.
A countersink cuts the tapered seat that lets a flat-head screw finish flush with the surface. This one has a 3/4" cutting body on a 1/2" shank, 2-3/4" overall, ground to a 60° included angle.
A 60° included angle is the usual choice for deburring and for centring work.