This filter is designed for diving fans who like taking photos and videos under water for Gopro 3+4.Due to wave refraction, pictures taken underwater may suffer color distortion.Using this color correction filter, pictures taken under water will be more lively and natural.Directly use on the Waterproof lens cover ,very convenient.Red: the depth of 10-20 meters, around noon (Sun beat down upon the water) you can use red, smoke filters, aimed primarily at restoring water absorbs Red. High Quatily Red Underwater Diving UV Lens Filter for GoProHero3+ 4(For 40m Housing) Color:Red ModelNo.:GO89RE Specifications: Type: Lens Filter Suit for: Gopro 3+ 4 Item size: 5 * 5.3 * 1.2cm / 2.0 * 2.1 * 0.5in Item weight: 15g / 0.5oz Brand No Brand SKU 28853_NP-1020533081 Filter Attachment Type N/A Water Resistant Yes