Rotozip 8-Pack 1/8" Standard Point Zip Bits are designed for basic drywall cut-outs. They have a spiral flute type and a 1" flute length. The shank type is spiral and the shank diameter is 1/8". The bits are made of steel. These bits are made of high-speed steel with a cutting depth of 1-1/2 inch and are used for basic drywall cut-outs when a slower, controlled cut of outlet boxes in drywall is needed.