Dirt Devil 120000 Series Upright Style 20 Flat Belts 2 Pk Part # 3JZ0900000 Dirt Devil & Royal Model 120000 Series Upright Vacuum Cleaner Style 20 Flat Belts 2 Pk{ 2 Belts Only } Genuine Part # 3JZ0900000 Replace your belts every 3 to 6 months.