I'm going iPhone 5c to iPhone 4 so i need a sim to fit?

I'm going iPhone 5c to iPhone 4 so i need a sim to fit?

Added (1). i have an iPhone 5c and i need to change my sim cards from a nano to an iPhone 4 one

I'm with optus australia… Just needing to know how to get them to send me a sim card to fit the size… If they do that

and any other details

Why would you downgrade? That's just stupid!

Just pick up the sim from any Optus shop and request them to transfer your details to the new sim.

By the way, why are you downgrading?

Just to go a store & ask for a microSIM with your number on it. That's it.