5 Sanitaire Commercial & Eureka Upright Style RD Round Belts Part # 52100C-12,52100C 5 Sanitaire Commercial & Eureka Upright Vacuum Cleaner . Style RD Round Belts Fits With Models : 600, 1400, 1900, 2000, 2100, 4000, 5000, 6400 and 7500 series uprights. Genuine Part # 52100C-12,52100C Replace your belts every 3 to 6 months.