Patriot EP Series 128GB UHS-1 SDXC Memory Card With Read Up To 50MB/sec - PEF128GSXC10233 Complies with SDA 3.0 specifications (host device must support SDXC for 64GB and 128GB) speeds up to 50MB/sec read and up to 35MB/sec write (Speed is based on internal testing on SD 3.0 and UHS-I mode environment) Performance may b e lower depending on host device. UHS-I (Ultra High Speed) Compliant Class Speed 10 Write protection switch to avoid accidental data deletion Voltage Range: 2.7 - 3.6V