What is a benik vest?

Weighted neoprene. Benik vests are thick vests, usually made of material like neoprene, with weights that can be attached at various points to help with posture, balance, and core strengthening. These are used for children with low tone in these muscles, such as those with cerebral palsy.
Http://www.benik.com. Benik is the company that manufactures all sort of supports for different areas of the body. Vests are for the thorax.