What SIM card will activate my iphone 5 activation screen?

I bought my AT&T iphone 5 and I never had a sim in it or any service on it I only used it with Wi-Fi at my home but I forgot my password and had to restore it to factory settings (dfu mode). Now it's asking me to put in a sim for activation. Can I purchase a empty sim so it can activate, can I put any sim in it so I can go pass the activate screen and start using my iphone again? Help please. I don't want to get any kind of service or plan yet an just want to use my iphone again. What sim will work?

You'll need any active at&t iphone sim for that