uxcell Straight Shank 8mm Diamond Drill Bit Tile Glass Hole Saw 12 Pcs Product Name : Glass Hole Saw;Main Material : Metal Cutting Hole Diameter : 8 mm / 5/16";Shank Size (Approx.) : 18 x 5 mm / 0.7" x 0.2" (L*D) Total Length : 51 mm / 2";Color : Silver Tone Weight : 50g Package Content : 12 x Glass Hole Saws