The lee bug underwater filter kit is for designed for use with the gopro hero 3 and helps to counteract the colour casts that are inherent in underwater photography the underwater filter kit includes 1x lee bug filter holder 1x green water filter magenta 1x blue water filter red a protective pouch and a cleaning cloth the blue water filter is designed for use in clear tropical waters to a depth of approximately 18 metres while the green water filter is suitable for fresh or seawater