Why does my iphone 4 from verizon have no sim tray?

On my iphone 4 from verizon (CDMA) there's no sim tray, I've been wanting to change the middle bezel from the regular brushed chrome to an all black mid frame. All the mid frames I have found all have the sim tray but my phone doesn't have one and I don't get why. I need info on why my phone has no tray or where to get a black mid frame that doesn't have a sim tray slot.

Its a CDMA only phones
CDMA only phones don't use SIM cards

the only phones Verizon carries with SIM trays are some world phones, and their new LTE line of phones.

You sure it's an iPhone and not a knock off?

I believe only the iPhone 4S & iPhone 5 have SIM card trays. The iPhone 4 is a CDMA only phone from what I understand.

Verizon doesn't use sim cards.
Therefore you can't unlock it.
The verizon iphone is CDMA.