Help identifying iphone 4 or 4s

I'm buying an iphone online and the buyer is convinced that the phone is an iphone 4 but when I looked up the model number it shows up as a 4s. It's a sprint phone and the model number is A1387 EMC 2430

ID Number BCGE2430A

can anybody help me?

If you press and HOLD the home button on an IP4S you get Siri which us not on the IP4