Description :
SP219: One Tuning Fork 256Hz, with wooden hammer
SP240: Two Tuning Forks 256, 440Hz, with wooden hammer
SP241: Three Tuning Forks 256, 440, 320Hz, with wooden hammer
SP242: Four Tuning Forks 256, 440, 320, 384Hz, with wooden hammer
SP243: Two tuning forks 256 Hz on individual resonance box. Supplied with
one adjustable mass for varying frequency, with wooden hammer