Consists of 13 aluminum tuning forks (G-100, C-128, C-256, D-288, E-320, F-341.3, G-384, A-426.6, B-480, C-512, C-1024, C-2048, and C-4096) packaged in a wooden box. Includes a mallet with both a hard end (for high-frequency forks) and soft end (for low-frequency forks). Forks are stamped with frequency and note.