This listing comes with the tuning fork only.
This tuning fork uses the A - 432 hz tuning system to tap into the Pythagorean spiral. There are thousands of different tuning systems and many arguments that can be made for and against any of those systems. Try different systems to see what works for you!
Start here with this 432 hz tuning fork and begin to experience the power of tuning forks from Biosonics.