Mastercool Flaring Tool
If you are going to do a lot of brake lines or other double flare style lines you have a lot of option. The best one that I have tried is the Mastercool 71475 Universal Hydraulic Flaring Tool Set. This kit fabricates Push Connect 1/4, 5/16 and 3/8”; GM Fuel Line Flare, Brake Lines and Transmission 5/16 and 3/8”; Flare/Double Flare 3/16, 1/4, 5/16, 3/8 and 1/2”; Metric Bubble Flare 4.75, 6, 8, and 10mm. It Comes in a custom molded box. The tool is quality made and the adapters are thick and solid. About the only issue with this is it is a bit more difficult to flare lines on the vehicle due to the size of the unit. Other then that, throw away the old style tool and get one of these!
Hydraulic Flaring Tool
This is an excellent kit. It has a lot of options for different types of flare ends. One thing that I really like is the dies that clamp the line are made with thick steel and really grab the line to prevent slipping. This kit cost in the $300-$350 range and if you are doing a good amount of lines you will not be sad you spent the money.
This is one half of the flaring die. They are solid and have enough grab for just about any type of line and flare.
Hydraulic Hand Press
This is the handle with the hydraulic press. It's as simple as squeezing the handle and the ram moves the die forward into the flaring form.
Close Up of Double Flare
This is the tool that you would use for a double flare. The kit comes with a variety of styles. Mastercool may also have other options Flares and Dies like 37 degree flares for AN fitting.
The fuzzy picture shows the types of flares that the tool can do.