Drill holes in both flat and contoured glass</br>Diamond-impregnated cutting bit for long life</br>Diamond grit around the circumference of the bit allows it to rasp a larger hole if needed</br>Holes on the side of the bit allow the removal of material</br></br>Product Description</br></br>This diamond-impregnated core-style bit features superior long life and is ideal for drilling in both flat and contoured surfaces. Diamond grit a full 360-degrees around the circumference of the bit allows it to be used in a rasping action to enlarge a hole if needed. Holes on the side of the bit allow the removal of glass dust from inside the bit. Each bit is packaged with Dremel cutting oil to increase the speed of cut and prevent damage to the bit from overheating.</br><br/>http://www.amazon.com/gp/product/B004Q03YXU