The 64Hz fork is longer than the 128 Hz fork, and sounds an octave lower.
The 64 Hz fork is best used for being placed on the sacrum in the lower spine to balance the autonomic nervous system.
The 128 Hz fork is used to help joint mobility. It’s great for loosening tight muscles and it helps balance the autonomic nervous system.
This fork is tuned to 111 Hz. This is the difference tone common to the Solfeggio tuning forks.
The 8 fork Harmony set is based on Pythagorean Tuning, rather than the traditional Tempered Tuning.
The Chakra tuning forks generate the 7 planetary audio frequencies of the 7 Chakras. They are also available as an 8 fork set with the Soul Star, and a 9 fork set that includes the Earth Star.