These short pattern wood beaver drill bits are only 120mm long. When running a cable or pipe across the run of the joists, their short length enables you to get between the joists. The four flutes and four cutting edges offer rapid cutting with fast waste removal, whilst the four cutting spurs result in a clean break through. Designed especially for cordless drills, the short body length means as little friction as possible when drilling thereby maximising your battery's power. The 1/4" hex shank ensures these bits are easy to change in a chuck or hex bit holder.