Maspen 20pcs 1GIG Bulk Pack USB 2.0 Flash Drives Swivel Thumb Drive Memory Stick, Black About Maspen * We are professional USB flash drive manufacturer. * All the USB thumb drives are double tested and formatted one by one before delivery. Tech Specifications: Chip: Grade A Size: 2.25 x 0.62 x 0.39 inch Weight: 4.3 ounces Interface Type: USB 2.0 (backwards compatible to USB 1.1) Compatibility: Desktop, Laptop, Macintosh, Tablet, Speakers and all with USB port, including some old machine, like embroidery machines, printers and more Operating System: Windows 7/Vista/XP/2000/ME/NT/98,Linux and Mac OS Operating Temperatures : 32°F to 140°F (0°C to 60°C) Storage Temperatures: -4°F to 185°F (-20°C to 85°C) Package Included: 20 x 1 GB USB Flash Drives Friendly Tips: 1. Some of the listed capacity on the USB flash drives is used for formatting and other functions, thus is not available for data storage. As such, the actual available capacity for data storage is less than what is listed on the products. The actual available capacity is around 1.84GB 2. FAT is factory default drive format, which is read/write compatible with Windows and Mac OS; while NTFS is compatible with Windows but semi-compatible with Mac OS. Please format it properly if need. Service: Thank you for choosing our products. If you have any problem during shopping, please do not hesitate to contact us. We are striving to be a trusted partner and seek to achieve 100% customer satisfaction.