D3O Intelligent Shock Absorption is a patented, shock absorbing material, engineered with Intelligent Molecules that flow with you as you move, but lock together on shock to absorb the impact energy. D3O is rate sensitive, meaning that when moved slowly, the molecules flow freely, making it soft and flexible. At high speeds however--like in an impact--the molecules lock together, making the material an excellent shock absorber. The whole process occurs instantly, returns to its original state as soon as the impact is over, and is repeatable. These qualities make it perfect for any application where you need total freedom of movement and excellent shock absorption. D3O is also extremely low profile, meaning it integrates seamlessly into garments, so neither style nor function is compromised.