Crotchless is a given, as it has basically no material.  It is a G-string back that continues to the front.  It has a small jewel that sits in a sensitive area.  There is then a little ring that attaches the g-string to the waist band.
This item is not built for comfort but rather the view.  It frames your area nicely and allows easy access to the sensitive areas.  These are fun and reasonably priced.  A nice surprise for your special someone.