High Light Intensity: Contain 6500 K white light, 450-495 nm blue light, 495-570 nm green light and 620-750 nm red light. LUX: 5000; PAR: 95; CRI: 96. The aquarium light with full spectrum can reproduce the real colors of objects to relieve the visual fatigue, and thus improve the comfort of the environment. For 18" to 24" Tanks: With an extendable bracket (min length: up to 18.5"; max length: up to 27"), the LED aquarium light always stays steady on the fish tank. Work best on tanks of 18 to 24 inches long. 24/7 Natural Mode: The LED light automatically starts at 6 a.m. and turns off at 10 p.m. Simulate the natural changes from sunrise, sunset to moonlight throughout the day, greatly energizing your fish and giving them a sound sleep. D/N Mode: Customize the daytime and night working hours with the IP68 waterproof fish tank light. Daytime duration: 6 h, 8 h and 10 h; Night duration: 2 h, 3 h and 4 h. Simulate the daylight and moonlight to create a natural environment. DIY Mode: The multi-colored LEDs allow you to set the starting time through the “hour” and “minute” buttons. It also provides 10 adjustable levels of brightness. Freely adjust the luminance for the growth needs of your fish. Pawfly Aquarium LED Light for 18" to 24" Tanks 24/7 Extendable Fish Tank Light with Full Spectrum IP68 Waterproof Light with D/N Mode Single Color Effects Timer and Adjustable Brightness