I first came across this in Antarctica, where a fellow visitor to Union Glacier Camp was sporting one. This ended up solving a long-standing problem for me. The conundrum is as follows: If I don’t wear a balaclava in very cold weather, my face and neck freeze. However, if I do wear a balaclava, the portion covering my nose and mouth gets wet and gross and often freezes over. This Seirus balaclava-like mask fixes this entirely, as a section can be flipped up or down with ease using a magnetic release. This has been an absolute godsend for skiing and other winter sports.