GREAT FOR GETTING INTO TIGHT SPACES ATTACHES TO ANY 3/8'' OR 1/2'' ELECTRIC OR AIR DRILL 3/8'' KEYLESS CHUCK BALL BEARING SHAFT SUPPORT IDEAL FOR DRILLING CABLE PATHWAYS BETWEEN STUDS AND JOISTS, KITCHEN CARPENTRY AND FITTING LIGHTWEIGHT, COMPACT DESIGN CASE QUANTITY : 6/24 NO INNERS FULL PRODUCT DIMENSIONS 20x14x6