Hi. I have a Verizon Iphone 6 now and was wondering if I would be able to insert a US Cellular sim card and use the phone on their network. I work in a large automotive manufacturing factory and don't get good signal inside the building, so I would like to try out the US Cellular network, but don't want to buy a new phone if I don't have to. I thought I have read about the Iphones from the 5 and up on Verizon having an unlocked sim slot, but I don't know if that's only for GSM networks and not CDMA networks. Thanks for the help!