SM-G996B is the Galaxy S21 Plus
The letter after the digits is the region: SM-G996B is the international version sold in Australia, and /DS means dual SIM.
For your Galaxy S21 Plus
Not sure what’s wrong with it? Diagnostics at Riverwood Plaza are free.
Free tools for your Galaxy S21 PlusCheck it yourself
Where to find the model number.
Settings → About phone → Model number. Got a different number? Look it up here.
Cracked Galaxy S21 Plus? We fix it while you wait.
Screens, batteries and charging ports at Riverwood Plaza. Free diagnostic, no obligation.