Features: Standard back size protector supplied with most men's jackets. Advanced, patented polymer, D3O® impact protector. D3O® impact protectors utilize intelligent Molecules that lock together on impact. Because of this, the impact protectors can be made thinner and lighter, making a jacket more comfortable and easier to wear. Decreased size does not come at the expense of impact protection. Back Protector EN1621-2: 2014 Level 1. 100% D3O® Impact Print™ Polymer. Fits Varial jackets size L and greater.