9x12 Inch Dry Erase Boards, Classroom Whiteboard for Students, Double Sided, Set of 10 Each of the large Aluminum

Each of the large Aluminum Alloy tuning forks is hand ground to high accuracy and has a frequency of 440 Hz (hertz=cycles / second)

5 packets of Cotton Wool

Output accuracy: Voltage: 0

Premium Craftsmanship: High Grade construction all the way through from the neck to the mouthpiece

9x12 Inch Dry Erase Boards, Classroom Whiteboard for Students, Double Sided, Set of 10 Each of the large AluminumPerfect for Classrooms. Dry Erase for Easy Cleaning. Slim Design & Reusalbe. Premium Quality: This item is made of high quality, heavy duty and durable materials. Designed for use in classrooms, household and educational settings. If you need custom order with different sizes design, please contact us. Safely Packaged to avoid being damaged during transportation.