Great vent for many differing applications. Can be used on the inside or outside of a sealed device. Allows pressure to escape from your sealed unit without letting in dust or water... The water entry pressure rating for this vent is 200kPa - which equates to 20M depth. The vent allows air to pass through, so if the sunlight hits your device and heats up the inner air it will expand, placing high pressures on your device's gaskets/seals, with our vent in place that pressure can be released from your device ensuring those seals are never placed under such pressure. This one factor alone can increase the lifespan of your product.