The Perfect Cutting tool made of Steel and Corrosive-Proof Composite Materials for Soft Copper, Aluminum, and Thin Wall Metal Tubing, Water feed lines, Ice Machine Hook-Up, Sink/Dish Washer Installation and Water softener Tube Caliper: Place tube on "V" groove and bring cutter down until it touches top of tube and read tube. Features: * Automatic Feed Feature. * Dimensional Tube Caliper O.D. Tube at a Glance * Hardened Tool Steel Cutting Wheel and Unique Reaming Blade. O.D. Sizes: 1/8~1"