This is a 5-pack of 7in USB 3.1 male to USB 3.0 female black adapter cables. Each allows your USB 3.1 (C) equipped MacBook, laptop or PC to connect to any USB 3.0 (A) equipped device, such as a mouse, keyboard, thumb drive, or external hard drive. Our adapter cables are backed by a 3 year warranty and are guaranteed to work the first time.This is a 5-pack of 7in USB 3.1 male to USB 3.0 female black adapter cables. Each allows your USB 3.1 (C) equipped MacBook, laptop or PC to connect to any USB 3.0 (A) equipped device, such as a mouse, keyboard, thumb drive, or external hard drive. Our adapter cables are backed by a 3 year warranty and are guaranteed to work the first time.