Great vent for many different 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 - we recommend setting you max to 10-12M though. The vent allows air/gases to pass through.  If the sunlight hits your device and heats up the inner air that places big pressures on your device's gasket/seals, using our vent that pressure can escape from your device ensuring those seals are never placed under such pressure. This is one factor which increases the lifespan of your product. This scenario also helps prevent condensation build p within your device too.