Which is better? Yamaha 5c or 4c clarinet mouthpiece?

Question:I know neither are great, but a friend of mine has a Yamaha 4c mouthpiece in pretty rough shape.
I have a new 5c mouthpiece that I don't need/use, so I'm thinking of borrowing it to him.

Is their that much difference? Which one is better?
I don't want to give him a worse mouthpiece.
I'm talking b flat clarinet here. Thanks!

Best Answer - Chosen by Asker: I know neither are great, but a friend of mine has a Yamaha 4c mouthpiece in pretty rough shape.
I have a new 5c mouthpiece that I don't need/use, so I'm thinking of borrowing it to him.

Is their that much difference? Which one is better?
I don't want to give him a worse mouthpiece.
I'm talking b flat clarinet here. Thanks!

4c is for beginners
5c is for high end beginner/intermediate players