The size of the expanded tubes: 6/8/10/12/16/19/22 mm (1/4" 5/16" 3/8" 1/2" 5/8" 3/4" 7/8"). Material: Alloy steel construction, with strong bracket, sturdy and durable to use. Application: Suitable for copper pipe expansion, ideal tool for air conditioning maintenance and pipeline maintenance. Convenient: Human body engineering design and built-in strong return spring, no need to press the handle very hard when expanding the tube.