[Warranty Policy]: 12-month warranty, our products are of good quality and we promise that any problem about the product within one year since you buy, it will be guaranteed for free. [Compatibilty]: Compatible with USB 2.0 and below. Works well on PC, laptop, desktop and MacBook etc! It can be compatible with more devices to achieve high-speed transmission performance. Supports almost all operating systems including Windows 2000 / 7 / 8 / 8.1 / 10 / Vista / XP / ME, Linux and MacOs 10.3 and above. If there are special needs or the computer systems are older such as Windows XP or MAC, please format the flash drive into NTFS, then use the flash drives normally. [Plug and Play]: Plug and Play,no need to install any software or driver to use to the flash drive.memory sticks can easily store or back up photos,videos, significant files ,documents, movies, pictures, books, programs,designs and more. Suitable for storing digital data for school, business or daily usage. [Capacity]: The calculation method of 1GB(1000MB) is slightly different 1GB=1024MB, and some of the listed capacity of the Flash storage device is used for formatting, other functions and thus is not available for data storage. As such, the actual available capacity(3.74GB) for data storage is less than what is listed on the products 4GB. [Metal super mini Design]: Thumb drive is all metal, no cover design. Waterproof, dustproof, shockproof and antistatic! Small(sizes: 22x12x4mm) and easy to carry. [High Speed Transmission]: 4GB Mini USB Flash drives adopt International famous chips, with excellent transmission speed and more stable reading and writing speed! write speed 10-12 Mbps, read speed 25-30 Mbps.