imei slotIn dual-SIM phones, IMEI-1 refers to the identifier for the first SIM slot. This number is used when the device connects to the network via the primary . It’s essentialA mobile phone has one IMEI number per SIM slot, so if you have a dual SIM phone, it will have two IMEI numbers: IMEI 1 for the first SIM slot and IMEI 2 for the second