They have options for a 7x1 x 1 1/4" arbor.
Be careful with that size if you find one and decide to use an arbor adaptor. This size is very common for vitrified wheels used on surface grinders. For your work OP, you want a resin bond wheel for a bench top grinder. You don't want one labeled as a toolroom wheel, you want one labeled as a bench and pedestal wheel. Also, you want aluminum oxide (A/O) unless you're grinding carbide, aluminum, or even cast iron, in which case green silicon carbide (S/C) would be used.
Nothing wrong with Radiac, Norton/St. Gobain, Carborundum (I think they're part of St. Gobain now?), Camel, etc.