Brand: AA Aquarium GKM makes fighting green water easier. UVC rays are effective in clearing green water or cloudiness The GKM9W Internal UV System with Power Head is for aquariums up to 50 gallons. - Helps keep your aquarium water crystal clear & reduce water changes - The GKM9W allows water flow in direct contact with the UV lamp, making it extremely efficient - Fast and easy installation, takes only 5 minutes - All GKM products are manufactured in an EPA Registered Establishment - After assembled approx. dimension 4" x 4" x 12" long. LED signals need for a UV Bulb replacement, easy change without tools - Complete set includes: Water pump, Sealed UV bulb, Control Box, Adaptor. UL listed