I use Dowell i 13 14, dual card dual standby, but I don't know where to put the SIM card.

The GSM card slot of Victoria i 13 14, that is, the one on the right is a second-generation (2G) mobile phone system, which can be used to install mobile or Unicom 2G card numbers. WCDMA card slot, that is, the one on the left is the third generation (3G) wireless communication technology, which can only hold Unicom 3G card numbers. So, if your mobile phone card is not 3G, put it in the card slot on the right, and only Unicom 3G cards can be put in the card slot on the left. PS, Victoria i 13 14 Front camera 1.3 million, video call is very clear.