SanDisk® microSDHC™ mobile memory cards are the ideal companion for multimedia phones because they plug right inside the phone providing immediate expansion of memory storage needed for carrying more music, video, photos, games, and mobile software applications in the latest generation of phones. Manufacturer: Sandisk Item model number: SDSDQM-004G-B35 Type: MicroSDHC Flash Memory Card Speed Rating: Class 4 Capacity: 4GB* Minimum transfer rate: read.: 4 MB / s min, write.: 4 MB / s PU: 1pc mini case (Blister) Special features: **5 years SanDisk limited commercial warranty, only for SDHC compatible devices, SD adapter not included. **Details about commercial warranty available on manufacturer official website. It’s of great importance the client verify previous to any memory purchase the official device documentation state its compatible with the new SDHC standard and the desired capacity. Part of the capacity is used to format and perform other functions and thus is not available for data storage. 1 megabyte (MB) = 1 million bytes, 1 gigabyte (GB) = 1.000 billion bytes, 1GB = 0.93Gib/953.67MiB Write and Read Speeds as stated by manufacturer, specifics may be obtained contacting directly their technical department. Reflected speeds may not be attainable under some circumstances, and depend on hardware, software and settings used. x=150KB/sec