Two lights for use open top aquarium saltwater marine and actinic. One very bright 10K the other purple for corals. Each light 36 watts and 40 inches long but can span up to four foot tanks. These were plugged in but not used and the 10K is very bright and the other purple color. These retail over $200 I believe each but I am not doing saltwater or coral so time to let them go. They don't have the bulky transformer so they plug in easliy to a timer. These are supposed to be water proof for short times if they fall into tank and can be used without a cover. As old leds burn out new ones are supposed to help out or that is the technology they are claiming.