Works On: 505, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 560, 561, 562, Sanitronic 7, Dual Sanitronic 50, Dual Sanitronic 80, Classic models, Tradition, Heritage, Heritage II, Legend, G3, G4, G5, Gsix, Ult G, Ult G Diamond, Sentria, Sentria II, Avalir, Avalir 2, and Avalir Platinum. Kirby genuine belts are specially designed and manufactured to maintain peak performance of your Kirby home care system. While imitation belts are available, they may stretch and break, damaging the Kirby system and your carpeting. Kirby genuine belts are properly sized and custom engineered for optimal performance with the belt lifter. If you need assistance in changing the belt, please call 1-800-437-7170 or watch this how-to video: Learn how to change a Kirby vacuum belt.