The Coastal Scents Italian Badger Buffer brush (review) used to be my favorite brush for applying my setting powder. Lately, it has been giving me a rash when I use it in a tapping motion.
The Sephora Professionnel Contour Blush Bronzer Brush #43 is very similar to the Coastal Scents Buffer brush. It has a flat top and is ideal for buffing. I much prefer the Sephora brush because it's a little bit denser, wider and much softer.
When I go overboard with my blushes and bronzers, the #43 is my go-to brush for buffing out over applied products. It's also nice for applying setting powder if you want more coverage and I highly recommend it if you use powder or mineral foundation because it'll give you an even application and better coverage.
Note: The Sephora brush measures 6 inches in total. The head of the brush is a little less than an inch tall.
It costs $36 at Sephora.