[AUGUSTEESHWARAN]

Micro sd cards which class is best for Lumia 720?

[MDK22]

s/b at least class 6 or higher - optimum Class 10 UHS1

... if you buy a class4 card, it'll work, but ultimately your (micro) SDcard apps will lag

[xandros9]

Depends on how much you want to pay.

put simply, a higher class means the card has a higher top speed

now a class 10 would be better than a 6, 4, 2, but get what you can afford/need.

I would say a class 4 or 6 is a good bet, 10 is preferred for high performance needs