niu go21, User Manual, Page: 45 / 66

EN
3. Insert the battery.
4. Replace the battery cover
Insert a memory card (optional)
To store additional multimedia files, you must insert a
memory card.
Your phone accepts memory cards up to 32 GB (depending
on memory card manufacturer and type).
•
Formatting the memory card on a PC may cause
incompatibility with your phone. Format the memory
card only on the phone.