So the Demon Snow Hyper Vest is an interesting low profile design. They really market the D3O but it’s only in the shoulder pad. It’s not in the back or chest protector. That is some type of memory foam. Many of the competitors have D3O or something similar like visco elastic polymer throughout the entire jacket. Again I’m no expert but I’d rather sleep on memory foam than land on a thin layer of it at 30mph. Still it’s not a bad option for the around 200 price range and it has a pretty low profile….especially around the shoulders which is usually the part that needs to be the lowest.