Product Name : Hinge Boring BIt;Suitable for : Wood CuttingDrilling Diameter : 70mm / 275; Size(Small) : 24 x 95mm/094 x 037(L*D) Size(Big) : 34 x 155mm/13 x 06(L*D); Length : 80mm / 31Material : Metal, Carbide;Color : Gray, BlueWeight : 171g;It can enlarge existing holes with ease and can bore any arc of a circleCarbide tip is specially designed to pass through hole cleanly in end grain and thin stock, great for boring concealed hinges and door clocksShould work with an electric drilling , which is not included here.Package Content : 1 x Hinge Boring BitNote:Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.