Unlocked IPhone 6 or 7 for camera use only

There is no such thing as an Apple refurbished device on Amazon. The only source of Apple OEM refurbished products is from Apple itself, in the online Apple refurb Store.

Amazon sells Amazon refurbished devices. Whatever they mean by “refurbishment” will be defined by them. Whatever warranty those devices have is from Amazon, not Apple.

You cannot complete iPhone setup without a SIM present in the phone. That SIM need not be associated with any active cellular service account though. After being setup, an iPhone will work just fine as a WiFi only device (it’s effectively an iPod Touch then, or similar to a WiFi only iPad). Other than being needed for cellular telephone function and SMS/MMS texting, there is nothing about an iPhone nor iOS that requires a cellular telephone service account.

You’ll need a nano-SIM for an iPhone 6 or 7 or newer. So if that older SIM is a nano-SIM it may work. If not, you can borrow a nano-SIM from someone for 2 minutes to complete setup - iPhone activation and setup does nothing to the SIM itself and has nothing to do with cellular service. It’s checking activation lock with Apple, and then enabling the device for use in the Apple iTunes and App stores.

Once you complete setup, you can take the SIM back out. You’d only ever need one again if you restore the device back to the initial setup state.

Note that if it ever needs service, Apple won't touch that phone.