No, Jen Selter does not have butt implants - she worked for that ass!
She's got a few fitness videos out, but it's basically a bunch of training and muscle building to get her ass looking like that.
Technically, not everyone can have an ass like Jen Selter's because it also depends on your leg shape, how your body builds muscle, and how your metabolism copes with the intense work outs.
Anyway, to answer your question.. They are 100% real, and you can tell by looking at photos of Jen Selter in bikini bottoms. If they were implants, it would be a lot more obvious because the shape would not have a natural curvature.
