The QEP Xtreme 1-3/8" Diamond Hole Saw for grinders is up to 50% faster and lasts up to 12 times longer than standard diamond drill bits. It is designed for easy, fast and accurate cutting of porcelain, ceramic and glass tiles. It features a special diamond grit edge for faster and smoother cuts. Simply dip in water, no need for a constant water delivery system, for quick and easy use.