There is no mobile power comes with the backpack inside.
There are two models,With USB and Without USB.
Large size :48cm*31cm*17cm,fit 15.6 inch laptop
Middle size : 43cm*26cm*12cm,fit 13 inch laptop
1 Inch = 2.54CM; 1 CM = 0.39 Inch.
Please allow 1-3cm (0.4~1.18″) differences due to manual measurement, thanks.