The evolution pro signature graphic features tsg39s trademark of a low and snug fit the evolution helmet sticks to your head like no other shell anatomically shaped this tsg bmx helmet smoothly curves around your head for great fit and wearing comfort tsg took a complete new approach when developing the evolution as the bmx helmet is not only molded on the front and back as with most common half shell helmets but is also greatly shaped on the sides the evolution is the choice for almost