USB Male to Barrel Male Charging Cable - Extra long 78in = 200cm - Replacement for Most Book Lights and OLDEST model of Ecologic Mart Reading Lamp/Music Stand - Plug 3.5mm OD x 1.3mm ID x 11mm L Extra Long 78 inches (2M) Lenght Being so long allows you to work comfortably on your cell phone or with book light while charging. USB 2.0 Male To Barrel (coaxial power connector) 3.5mm Cable. Barrel Type: 3.5mm OD (outer diameter) x 1.3mm ID (inner diameter) x 11mm L (length of barrel). Useful to charge any device with 3.7 to 4.2V - 800 to 2100mAh Lithium Ion Battery WARRANTY AND SUPPORT: Try it now and enjoy 30-day money back guarantee and manufacturer's WARRANTY