, Over 50 million Memory cards sold , Look for the U3 icon - This indicates a high-speed card. U1 cards are standard speed , Look for the read and write speed. Standard cards only indicate the transfer speed (read). buy a premium high-speed Memory card at a standard price , Premium high-speed performance: up to 100MB/s read speed and up to 50MB/s write speed , High temperature resistance, water resistant, Shock proof and X-ray proof , We hope you appreciate our green packaging to reduce environmental waste ,