HD stands for "high definition.” HD Lace is a royal lace material that is also called Swiss Lace, which is invisible when applied to the scalp. This ensures that the wig-wearer can have an exposed hairline, which looks very natural and renders the lace along the hairline highly undetectable. 
KIM & C Premium HD Stocking Wig Cap is thinner and more breathable than ordinary mesh caps. It looks more natural and fits well. When you wear it, it basically matches your skin tone.
Invisible
Lighter & more durable
Super stretch
More comfortable
Ultra sheer
No slip off