What does U3 mean?

U3 is a UHS Speed Class rating that indicates a microSD™ card can maintain a minimum sustained write speed of 30MB per second. This level of performance is commonly recommended for many compatible devices that record 4K video or capture high-bitrate footage. Unlike maximum advertised speeds, the U3 rating reflects sustained recording performance, which is particularly important when recording longer video clips.

Every TrailBit™ microSD™ card is validated to the U3 performance standard, providing dependable recording performance for a wide range of compatible cameras and recording devices. When combined with UHS-I technology and the V30 video speed class, U3 helps ensure your TrailBit™ storage system is capable of meeting the demands of many modern recording applications.