Not as advertised...
This product does not have two variables in coarseness. The file is the same coarseness on each side, and quite a rough one, I might add.  It's great for shaping, but it's supposed to have a less coarse side for smoothing and it doesn't.  I give it two stars for this reason - deceptive advertising - and I won't re-order.  I will try and find a file that really does have two coarseness variants.  I hate to leave a bad review but I think the public needs to know what they're really getting.
Rating: 2 stars