These two tuning forks manifest the sacred ratio of 8: 13. This interval is not usually found in contemporary music.
When sounded together, these tuning forks produce a sound that has been called “angelic”. Others have found it creates a spiraling effect. Since these tuning forks represent an outer spiral of the fibonacci series, this makes sense. People seem to journey within (or without to the Angelic Realms) when they hear the sounds of these tuning forks struck together.