9900 is just the mode number for the pair.
So what can you not charge this and do you need to buy an adaptor if no shaving plug?
Ordered 2 of these…I will return one once I choose the best out of the two.
Think I've got a pro 600? Fairly happy with that one so hoping this one will be brilliant lol. Other half can have the other or I spose I'll ebay it. Cheers OP (y)
Good price. Not cheap, but useful to essentially have a spare (or one to keep in the case for travel). Dropped my old Oral-B toothbrush (from approx 5 feet) and it no longer works... thanks OP