What SIM card should you get? Hmmm! It can be tricky! Just remember this: EasyGO Wireless and H2O Wireless operate on the AT&T GSM Network, so if you have good AT&T coverage in your area & an unlocked GSM phone, they are probably a good choice. The H2O & EasyGO SIM cards are the 3-in-1 SIM cards, so they include the Standard, Micro, & Nano size (all 3 sizes used today). The Page Plus Cellular 4G LTE SIM card, which operates on Verizon Wireless's network, is only for Verizon Wireless 4G LTE CDMA compatible cell phones. The Verizon Wireless 4G LTE SIM cards are the 2-in-1 Standard & Micro size, so make sure your cell phone will accept one of these sizes.