The Ista Marine Camera Filter uses a yellow lens to filter out blue light from your photos. This camera filter clips onto cell phones with a plastic back clip, covering your camera lens. Blue light from LEDs, especially in marine aquariums, can ruin photographs of your beautiful & colorful aquarium inhabitants. This filter allows you to take clearer and more lifelike photos, so you can share away on social media! Two camera filters included in each package, with a spare for you to use as needed.