Tuning Fork, Superior Quality, Set of 13. Range from 100 Hz. to 4028 Hz. Specifically the set includes 1 each of 100 Hz., 128 Hz "C", 256 "C", 288 "D", 320 "E", 341.3 "F", 384 "G", 426.6 "A", 480 "B", 512 "C", 1024 "C", 2048 "C" and 4096 "C". Set includes a rubber tipped mallet to serve as an actuator. The kit comes in an attractive Styrofoam and foam rubber lined wooden storage box.