High Speed Storage Media Cards. Take more pictures. Listen to more music. Store more files. SimpleTech Flash Memory Cards are designed for unlimited compatibility with digital cameras, music players, and other devices that use the selected media, and have low power requirements for longer battery life. Media Cards for use with Digital Cameras, PDA's, SmartPhones, Music Players, or any device that uses Media Cards MMC and SD are close in size. Phones with SD slots can take SD or MMC cards. MMC slots can take only MMC cards. Differences 1) MMC is less expensive, 2) SD has faster transfer rates, 3) SD cards have two settings: Locked and Unlocked to protect data. MINI-SD and RS-MMC Cards offers all of the benefits of SD and MMC but in a much smaller size. It can also be used in devices with SD / MMC slots by using an adaptor.