The Chinese have gotten much better with the Oral B toothbrush head counterfeits.

I bought some on eBay, advertised as genuine but not. The packaging was near perfect. The only thing that gave them away was the different mouth-feel and two misplaced mold release marks.

Genuine Braun dual-action brushheads have two divits on top of the brushhead. The copies have the two divits on the side.

I sent a note to the seller warning him that some counterfeits might have gotten into his supply. Seller refunded me.

If you get counterfeits from Amazon I am sure the 3rd party seller will refund you.