Quick daft wheel/tyre width question - Alex S500?

sarajoy Posts: 1,675
edited February 2009 in Commuting chat
I can't find any details online on the Alex S500 700C rims I appear to have - does anyone know what width they are? They currently have 28mm tyres and I wonder what the max and min tyre widths are that I can fit (I fancy trying skinnier).

Or does 'Alex S500' cover a truckload of wheels, so I'm just going to have to get in there with a ruler and consult the late Sheldon Brown?