Thinning Shears - scissors that are used to thin hair out. Instead of having two flat blades, like regular scissors, thinning shears have matching sets of "teeth" with gaps between them. When used to cut hair, some of the hair gets between the teeth of the shears and is cut, but most of the hair falls in the gaps between the teeth and is not cut. This allows some of the hairs to be cut short and other hairs to remain at the full length of the style. With some of the hairs cut short, this thins out the hair.