The Giro Sario MIPS Helmet and Article II Goggle are built to work as one system rather than two separate pieces of gear. The helmet's Stack Vent aligns directly with the Article II's own top vent, the exact spot where most goggle fog actually starts, so the two components clear warm air at the source instead of masking it after the fact. What Our Gearhead(R) Experts Are Saying:"Article II's wide field of view is exactly where fogging usually creeps in first, but lined up with the Sario MIPS's vent, mine stays clear through a full storm lap."