This cool skull mask is made of 100% Polyester. It has M-shaped nose clip. This is a cleanable, reusable mask that is also very friendly to skin. You Can Use it when climbing or cycling, or when commuting. You can also use it to keep warm in cold weather.It can effectively block the smog in the air and protect you from car exhaust. You can also change the filter as it has a slot in the interior of mask to replace the filter.