1. High quality physical experimental instrument, durable and practical. 2. The edges and corners are neat and the surface is chrome plated 3. The tuning fork set is used to demonstrate the resonance of sound in school. 4. Can be used as a Universal tuning fork of a variety of experiments, such as the sound of the occurrence, interference, sound conduction of various substances. Colour:wood color + silver Material:wood+metal type:B: 256hz 320HZ 384HZ 512hz Package Contents: 4 x Tuning Fork 1 x Hammer 1 x base Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.