Meldes Vibrating String Apparatus, consists of a string and an oscillator to generate different frequencies, Requires 6 V, 50 Hz power source, with 4mm plug leads, Weight (lb): 1.4, Length (in):11.0, Width (in):6.0, Height (in):3.0
Doppler Effect Demonstration Apparatus, 92dB buzzer, 0.8m tether. Nylon cord is 2ft 8in attached to a rugged ABS handle 8.5in long, (1in diameter), Swing the apparatus and students will be able to hear the change in frequency, Dimensions: 4.5 x 5 x 3 in