EelVision BG is recommended for blue and blue-green waters and GW for green waters, from 20 feet (6 meters) to 60 feet (18 meters). Well balanced color compensation and little exposure loss (f-stop 2/3). How to use? Installing and uninstalling EelVision filters does not require to remove any screws! Removing the lens screws to install filters increases the risk of flooding your camera and constitutes a modification of the housing, voiding the manufacturer"s warranty. 1. Remove the camera from housing. 2. Insert filter inside the rectangular lens compartment through the lens opening. The tab should be pointing left (looking inside housing). 3. Insert the camera back, making sure the tab is still inside the housing and not inside the lens compartment. 4. Close housing, get in the water! What"s included? Includes 1 (one) unit each of EelVision BG and GW filters compatible with the GoPro© HERO3 White, Silver and Black only. Disclaimer - Read and follow instructions prior to use; - We offer 100% satisfaction guarantee and a full refund if decide to return the item; - Handle filter with care, wipe fingerprints with microfiber cloth. Microscopic surface scratches will not affect video quality; - Depth guidelines on the most effective depths, dive site conditions vary (i.e. light intensity, visibility, etc.). - Keep filter and plastic packaging away from small children; - Designed for use with GOPRO® products. GOPRO® is a registered trademarks of Woodman Labs, Inc. in the United States and other countries. - Price does not include camera, housing or any other accessories depicted in the pictures in this listing, other filters.