4GB Perman USB 2.0 Metal Flash Drive Memory Stick Storage Thumb U Disk Key Stick Blue Capacity: 4GB. Compatible with USB 2.0. Speed: Writing Average 10-12MB/Sec. Speed:Reading Average 3-5MB/Sec. Speeds of up to for handling your large photos, videos, or other files in a fraction of the time. Supports Windows 7 / 8 / 98 / Me / 2000 / XP / Vista / Linux 2.4, Mac OS 9.0 And above Etc Computer operating systems. Compact, slim, and light weight. Effect of U disk read and write speed will be affected by temperature and transport.