Dual SIM Card Dual Standby (Two Micro SIM Card Slots, One TF Card Slot). Note：SIM 1 supports 4G/3G/2G, SIM 2 only support GSM network, no data network on SIM 2. NFC Function. Smart Wake. ASUS Zenfone 2 ZE551ML is equipped with fast access to all your appliacations; it allows for not only easier ways to use your appliacations, but also makes your button to last longer.