What types of pen drive or memory card you need to buy?

Do you want to buy a pen drive or memory card? Wait!!! I giving you a short tips for buy your new pen drive or memory card. Than you'll get good performance.
Memory card or pen drive getting in a cheap rate? 
Speed less?
Be cautions!!!
Check out the class of memory before you buy.

• Class 2 -------> 2 MB per sec.
• Class 4 ------> 4 MB per sec.
• Class 6 ------> 6 MB per sec.
• Class 10 -----> 10MB per sec.

So select your memory card or pen drive what types you need to buy.