The olympus ppo e04 is the lens port for underwater photography with the olympus zuiko digital 7 14mm ultra wide angle zoom 8mm fisheye and 9 18mm wide angle zoom lenses it is made from durable high quality aluminium with tempered glass and is waterproof to a depth of 60m to use the olympus zukio digital 7 14mm ultra wide angle zoom lens the per e02 is needed