Slot.it magnets?

Hi, can anyone please tell me the difference between the Slot.it SICNO7 and the SICNO6 magnets?, they look very similar to me, I want to buy the same one that comes in the Slot.it Porsche 956, I think it is the SIC06 I need?. Been trying to work this one out for months, and now I need to buy one, I still can't tell the difference between them!.

If anyone out there still uses magnets, would appreciate some help, thankyou. I would ask my supplier but, they often don't have a clue themselves!.