Application Performance Class can be applied to UHS SDHC/SDXC Memory Card product family.
＊Not only for storing maps, pictures, videos, music, dictionary and documents, the Application Performance Class 1 (A1) also enables user to be freed form sluggish for editing and updating data.
＊The Application Performance Class 2 (A2) makes SD memory card much higher performance than A1 performance by using functions of Command Queuing and Cache. Efficient flash memory management can be supported by Maintenance functions.

Reference soruce: SD Assocation

Those Symbols, Speed Class, UHS Speed Class and Video Speed Class with a number indicate minimum writing speed, are mainly useful for camcorders, video recorders and other devices with video recording capabilities. Regarding bus mode, it is necessary to use a bus mode fast enough that does not affect memory write speed. Speed Class C10 is used in High Speed mode or faster, UHS Speed Class U1 and U3 are used in SDR50/DDR50 or faster, and Video Speed Class symbols V60 and V90 are used in UHS-II mode or faster. Each Memory card has a symbols or mark on it describing the speed class. Users should choose the proporate card for the devices application.

*Remark: Video Speed Class is defined to answer a demand for high resolution and high quality 4K8K video recording and it also has an important feature to support next generation flash memory such as 3D NAND. Furthermore, as it covers speed of HD(2K) video, it is possible to integrate into Video Speed Class from now on.

*Refource source: SD Association

 

Please make sure the specification of the Memory Card is compatible with your device.
-SDXC Memory Card can only be used on a device that supports SDXC.
-SDHC Memory Card can be used on a device that supports SDHC and SDXC.
-SD Memory Card can be used on a device that supports SD, SDHC and SDXC.

All storage products will display less than stated memory capacity on a computer. The discrepancy results from different algorithms.

On a computer, 1GB = 1024*1024*1024 = 1,073,741,824 (1024 is 2 to the power of 10, which is the algorithm used by the computer)

For a 32GB pen drive, the computer will calculate it as having capacity of 29.80GB.
32,000,000,000÷1,024÷1,024÷1,024 ≒ 14.90GB.

Also note that each Flash memory may possess innate variances because of its manufacturing process. KINGMAX will therefore adjust the available space on the pen drive to store necessary firmware configurations or system data. Please be assured that we do so at appropriate measures and that your pendrive has the normal capacity.

(1) FAT32 is only supported by memory cards/ pen drives with capacity less than 32GB, and it does not support storing or transmitting any single file that exceeds 4GB in size.
(2) The exFAT file system was released by Microsoft to address FAT32's inability to carry files over 4GB. Also if the capacity of your memory card/pen drive are larger than 32GB, you could format it to exFAT.  It depends on the users' need to choose the file system to format the memory cards / pen drives.

Reasons causing memory card read failure are as follows:

1.  Power of camera is switched OFF while the camera is accessing data.
2.  Taking a picture when the battery is low.
3.  Withdrawing the memory card when the camera is accessing data.

The remedy to the above problems is to avoid incorrect use of the memory card. If unfortunately any of the above
happens, use PC and a card reader to re-format the memory card.

There are two main reasons for data corruption in a memory card.
1. Taking pictures or recording with a camera that is running low on batteries, or has an unstable power supply.
2. Removing the memory card from a device during a read/write operation. Please make sure that you have safely ejected your memory card before unplugging it from your device.

* Please format your memory card in the camera before using.

The majority of digital cameras only support the FAT format; if you have formatted the memory card in another format (NTFS or FAT32), your camera may fail to recognize the card. You will have to re-format the card by selecting the FAT format.

It is recommended to format a memory card before using it. For using on a cell phone or a camera, it is recommended to
format the card with the cell phone or camera intended to use the card since formatting with the intended device will
have preset directories created onto the card. In the case of formatting a memory card with a PC but using it on a
camera or cell phone, the device may have problems recognizing and utilizing the card.

1. Checking the compatibility of mobile phone the memory. 
Please check the specifications of your mobile phone and make sure the memory card is compatible with your mobile. Some mobile phone support less than 32GB memory card, and 64GB card can't work on it.

2. Formatting file system. With 64GB memory card supported the default format file system is exFAT and it may not work with the cards be formatted by FAT32. And you need to re-format the card on your mobile phone again.

3. The memory card might broke down. Please go back to the place you bought the card and check about the after service issues.

The size limit of an FAT32 single file is 4GB, therefore a movie exceeding 4GB cannot be stored. You may format your USB disk with NTFS format to enable storing single files that exceed 4GB.