Gliders and springs on Air Tracks make a beautiful harmonic oscillator with sharp resonances. The simplest resonator is a single Glider and two springs and has one resonant frequency. Adding a second Glider and spring adds another degree of freedom and a second resonance. The system has an additional resonance for each Glider added. The kit is supplied with five 150 g Gliders, six 2.5 cm long stainless steel springs, and five ceramic magnets for damping random motion. They provide a comprehensive course in vibration theory when set up on an Air Track. Including manual. Requires an air track (such as our model EA-01), sold separately. Pictured with Photogate timer and air track, both sold separately.