These are the smallest and lightest types of MP3 players, often no bigger than a pack of gum, and they typically weigh no more than 3 ounces. They have solid-state memory instead of a hard disk, meaning they have no moving parts and tend to have longer audio playback time than players that use hard-disk storage. Storage capacities range from 512MB to 64GB, or about 120 to 16,000 songs. (All song capacities listed here are based on a standard CD-quality setting of 128 kilobytes per second, which requires about 1GB per 250 songs. You can fit more music into memory if you compress songs into smaller files, but that may result in lower audio quality.) Some flash-memory players also have memory-card expansion slots to add more capacity. These typically use Secure Digital cards, though some Sony players use MemoryStick media. Memory-card capacities range from about 32MB to 32GB. Memory costs have gradually dropped. Price: $40 to $500 for the player; $10 to $20 for a 4GB memory card.
