The Samsung Galaxy S21 Ultra comes in a wide variety of model numbers. All of them begin with SM-G998 but the following characters will decide which version you get.
Comparison between: Samsung Galaxy S21 Ultra 5G SD888, Samsung Galaxy S21 Ultra 5G Exynos, Samsung Galaxy S21 5G SD888, Samsung Galaxy S21 5G Exynos
Samsung Galaxy S21 Ultra 5G SM-G998U1 256GB 12GB RAM US Version - Phantom Black : Cell Phones & Accessories
Galaxy S series - Browse Smartphones
Samsung Galaxy S21 Ultra 5G SM-G998B/DS 256GB 12GB RAM Factory Unlocked (GSM Only No CDMA - not Compatible with Verizon/Sprint) International Version - Phantom Black : Cell Phones & Accessories
OLED LCD Screen for Galaxy S21 Ultra 5G SM-G998B Digitizer Full Assembly with Frame : Cell Phones & Accessories
CELLPHONE SAMSUNG GALAXY S21 ULTRA 5G SM-G998U - A. Ally & Sons
OLED LCD Screen for Galaxy S21 Ultra 5G SM-G998B Digitizer Full Assembly with Frame : Cell Phones & Accessories
6.8 inch AMOLED for Samsung Galaxy S21 Ultra LCD G998U1 G998W G998B G998B/DS S21Ultra 5G LCD Display Touch Screen Assembly Replacement (with Silver Frame) : Cell Phones & Accessories
Samsung Galaxy S21 Ultra 5G SM-G998B/DS 256GB 12GB RAM Factory Unlocked (GSM Only No CDMA - not Compatible with Verizon/Sprint) International Version - Phantom Silver : Cell Phones & Accessories
Samsung Galaxy S21 Ultra 5G SM-G998B/DS 256GB 12GB RAM Factory Unlocked (GSM Only No CDMA - not Compatible with Verizon/Sprint) International Version - Phantom Black : Cell Phones & Accessories
Samsung Galaxy S21 Ultra 5G Needs Two Features To Justify No MicroSD Slot Model Numbers: SM-G998B/DS (Dual SIM Capable Smartphone) (Deemed As Zero Compromises.) : r/S21Ultra
OLED LCD Screen for Galaxy S21 Ultra 5G SM-G998B Digitizer Full Assembly with Frame : Cell Phones & Accessories
Samsung SM-G998U Galaxy S21 Ultra 5G UW Dual SIM TD-LTE US 256GB / SM-G998P (Samsung Unbound O3) - Frequency Bands and Network Compatibility
6.8, 1440 x 3200 pixels, Dynamic AMOLED 2X, 120Hz, HDR10+, 1500 nits (peak), 5000mAh Battery 128GB ROM, 12GB RAM, No SD Card Slot, Qualcomm SM8350
SAMSUNG Galaxy S21 Ultra G998U 5G | Fully Unlocked Android Smartphone | US Version | Pro-Grade Camera, 8K Video, 108MP High Resolution | 128GB