If you want to buy more than 20pcs these at once. You can enjoy a Group Buying Discount and save more money, Please contact us to note your wishing list, wish you happy shopping! Specification: Interface: USB 2.0 Material: PVC Capacity: 64M/128M/256M/512M/1GB/2GB/4GB/8GB/16GB/32GB Size: Approx. 55x57x9mm Weight: 17g Features: Fast Data Transfer Rate Read: 15MB/sec & Write: 6MB/sec. More Than 10 Years Data Retention. Good Compatibility Compatible with USB 1.1/2.0 Compatible with phones,tablet, or computer owning Type-C or Micro USB interface Support Windows 7 / 8,Windows Vista,Windows 2000,Mac OS X, Linux. Multiple Function Easy to read and read in high speed ,No need drive/power supply only plug in. Store your pictures, videos, and songs and any kind of data. Other Characteristic Hot plug & play Easy to carry. Cute style and fashionable products, as an impressive gift for your beloved, friends or even customers at Christmas. Environment: Operating temperature: 10 ℃ -40 ℃ Operating Humidity: 10% -90% Storage temperature: -20 ℃ -60 ℃ Storage Humidity: 5% -95%