This type of SIM isn’t a physical SIM but an electronic one that will be automatically downloaded to your watch from your phone during the initial pairing process.. I'm not sure myself as I've never set an esim for a watch up before. I'm guessing it will recieve messages and calls from the number your phone uses. It may show a different number for your watch esim, but is probably paired to your mobile number. Best thing to do is give your network provider a call and ask them.