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