MarineLand Advanced LED Strip Light for Salt & Fresh Water Aquariums Daylight LED Lamps provides brighter output than two typical fluorescent bulbs Lunar LED Lamps replicate the moon light cycle Integrated timer allows you to control the daytime and lunar settings automatically Adjustable mounting legs for flexibility in 18-24 aquarium widths Energy efficient for up to $50 in annual savings* and up to 5 year lifetime** Refer to the PDF attached below for Manual