The Persist was created for cyclist that look for a stylish helmet with a tailor-made fit. The adjustable VaporFit(TM) system provides a customized fit, while the MIPSA(R) liner adds an increased level of protection. The Persist features 21 optimally placed vents that work with internal air channels to keep you cool and comfortable. The AirEvac(TM) system efficiently pulls hot air off of your eyewear to prevent fogging. Pass-through channels allow eyewear to be easily stored on the front of the helmet. Product Details Protection Lightweight in-mold construction MIPSA(R) Brain Protection System reduces rotational forces caused by angled impacts to the head CPSC and CE EN 1078 certified Fit / Integration Designed for ultimate integration with Smith performance eyewear for maximum comfort, venting and storage convenience AirEvac(TM) ventilation system integrates with Smith eyewear for fog-free lenses VaporFit(TM) dial adjustment system offers 270-degree fit adjustment with the turn of a dial Features 21 fixed vents for consistent airflow Performance comfort lining Lightweight, low-bulk single layer webbing Weight (Size M, MIPSA(R)): 11 oz / 300 g