The memory card will be seen when buying

Source

Most users use memory card or external storage to increase storage on smartphones. From 4GB to 128 GB of memory card smartphones are supported. However, buying a memory card can not decide what to buy. However, while buying a memory card, keeping some things in mind, the problem will be solved.

There are several sizes of memory cards. Micro SD, SD cards have different sizes. Before purchasing, remember to support any size memory card on your phone or device.

Capacity

Source
Memory card storage capacities should be higher. This does not reduce the speed of the phone. Does not hang However, the maximum number of memory cards on the phone should be supported.

Classes

Source
There is a speed class on the back of the memory card. There are four classes of memory cards. Classes 2, 4, 6, 10. The more speed classes, the better the memory card will be. Speed ​​will increase from data-transfer to other works.