Urrea pipe die heads are used to create NPT threads. The fact that the thread is tapered allows it to create perfectly sealed joints between the pipe an other accessories. That is why it so important to have tools that do this task with a high degree of reliability. The set includes: 1/2" die, 3/4" die, 1" die, wrench handle, 1/4" pipe wrench, pipe pliers, professional pipe cutter and plastic case.