iwatch Model A1623

I was given a watch for Christmas and was told that it was the "first one". I tried searching the model number, which is A1623, but nothing came up. I cannot find a band that will attach because there is an electrical connector inside the band slot instead of a space for the band release button.

Does anyone know what model I have or what band I need? I've never used an iwatch before so I am completely at a loss.