If you get just one helmet, make it this oneWhether your finish line is on the race course or your front door, Trek Circuit WaveCel delivers the performance, comfort and tech to be your go-to helmet. It's equipped with features that any rider will appreciate, like WaveCel technology, a BOA Fit System and Blendr mount systems.WaveCel is a collapsible cellular structure that lines the inside of the helmet. This Trek-exclusive technology disrupts the safety standards that the industry has accepted for over 30 years.