smartphones -- Y31 and Y15S

Vivo has launched expanded its Y series with two smartphones -- Y31 and Y15S. Vivo Y31 features a 4.7-inch 720p HD display and is powered by 1.3GHz MediaTek MT6580 quad-core processor and 1GB RAM. The phone has 8GB of internal storage and can hold microSD card of up to 128GB. It measures 137.24 x 68.76 x 8.39mm and weighs 137 grams.