flat and hard [SEP] i am not impressed with these brush heads unfortunately the biggest issue is that they lack the two level bristle layout that the oral b heads have which help get in between teeth i feel like i have to work much harder getting my teeth clean because of these brush heads second they feel very stiff which adds to the issue of not getting in between teeth very easily the overall size and shape is similar but the more sculpted shape of the oral b seems to allow it to get a little further back in my mouth i have included a couple of photos to show the differences