All the features you love from the Smith IO series packed into their smallest size. The I/O MAG S replaced the I/O S from the previous seasons, but not without some killer upgrades. The old lens change system was good and pretty quick, but the new MAG interchangeable system is great and lightening fast. A small tab behind the strap quickly releases the lens from the frame so you can swap between lenses and get crystal clear vision no matter what the clouds are doing. With 9 lens options and 11 different strap colors, there is an I/O MAG S for every condition and every style.