Copper Pipe Tube 45 Degree Flaring Tool Imperial Standard Mastercool 70051.

Durable forged steel slip-on yoke. The flaring bar is hardened, highly polished and nickel chrome plated. Auto-centring yoke features bearing driven hardened cone for easy flaring.
Standard 45-Degree Flaring Tool flares 7 sizes: 3/16″, 1/4″, 5/16″, 3/8″, 7/16″, 1/2″ and 5/8″ O.D. tubing

Also Available:

70051-M: Metric 45 Degree Flaring Tool flares 7 metric sizes: 4, 6, 8, 10, 12, 15 and 16 mm O.D. tubing