The Digi Chip 256GB Micro-SD Class 10 memory card is a high speed memory card made using the highest quality Samsung memory chips. This 256GB memory card is fully compatible with Samsung Galaxy phones including the Samsung A23, A33 5G, A53 5G, M33, M53, F23 . They are also UHS-1 spec which stands for Ultra High Speed meaning they are some of the fastest mobile memory cards on the market. Digi-Chip is our own brand and we offer a lifetime warranty on all Digi-Chip products.