Hello dear friends, i would like to say about lenovo 10400 power bank.Now smartphones are our good friends.but the smartphone users facing a major problem that is battery backup.I am a regular user of samsung smarphones, the main problem of samsung smart phone is battery backup;3 year ago I bought a lenovo 10400 powerbankfrom flipkart.Many of my friends said that that is a very bad product and after few months it will useless;but after 3 years I am using the same product without any deffect. Lenovo10400 powerbank islight weight and the charging time is 5-6 hours;comparison to other power banks it have 2 usb sport we can charge 2 devises togetherwith this power bank .You can use the power bank for mobile phones, blutooth devices, fitness bands, wifi routers etc. I must say I am fully satisfied with this product