This bra gives decent encapsulation to trap each breast and make them stable both up, down, and side to side.  The nice thing is that you don't look totally squashed and uni-boob, and it's easier to get into and out of than an over-the-head bra.  Unfortunately, the smalest one they make is a 34B, and it fits like a 34C.

I normally wear a 32D, and the 34B fits properly, if only a little big in the band. No movement, nice smooth lining and elastic.  My rib cage is 28" where the band sits, so if you are smaller, none of the sizes will be snug enough.

Only two drawbacks if the size works for you: the front runs narrow (even on the photo models, you can see it) so you get a little bit of fat overspill at the outside edge of the strap where it meets the cup if you're not a hardbody.  Also, the stitching on the underside of the straps feels a little itchy compared to my other sport bras.