Plasplugs, 5/16" Cool Cut Tile Drill System, For Drilling 5/16" Holes Perfectly Through Any Wall Tile Type Ceramic, Porcelain, Granite, Marble, Natural Stone, Etc, Perfect For Bathroom Accessories Towel Rings, Robe Hooks, Paper Holders, Etc, As Well As Piping & Plumbing Work Toilet Bowls, Shower Heads, Hot & Cold Pipes, Etc, Long Life Resilient Diamond Tipped Hollow Core Drill, Patented Water Cooling System With Press Button Feed, Unique Self Adhesive Drill Guide For Precise Clean Cut Drilling.