Asiawill&reg; Professional Diving Housing Red Filter PC Under Sea Filter Cover for GoPro Hero3+ (Red) Asiawill Only for GoPro HD Hero 3+ This is the PC Under Sea Filter for covering and protecting the ring. PC Under Sea Filter Cover The Red Color Correction Filter is the most used in blue waters (bright days, shallow waters, etc.) specially used for recordings in less light or more depth situation, it helps you to capture the real colors.