Capacity 64GB Sequential Read Performance Up to 100MB/s Sequential Write Performance Up to 40MB/s Dimensions (L X W X H) 0.04" x 0.59" x 0.43" Speed Class UHS Speed Class 3 (U3) Video Speed Class 30 (V30) Compatibility For microSDHC (64GB) card: Compatible with microSDHC and microSDXC host devices For microSDXC (64GB, 128GB, 256GB) card: Compatible with microSDXC host devices.