The MEINL planetary-tuned tuning forks are made in Germany using the calculations of Hans Cousto (The Cosmic Octave) to match the frequencies of the sun, moon, and planets. Each one is tuned to produce the corresponding frequency of the celestial body. These tuning forks have been designed for use in therapeutic applications. Specifications: Size 7.3" / 18.5 cm Weight 78,9 g / 2.8 oz Material high-quality nickel-plated steel Frequency 172.86 Hz / F3 Feature 1 Handcrafted masterpiece Feature 2 Ergonomic shaped cork handle Feature 3 Engraved logo and tuning info Made in Germany Recommended Mallet SB-PM-SR-S