24w - Best Suitable for 15" Aquarium Unibody design with whole aluminum housing, slim & exquisite looks, quite working Built-in controller with timmer & dimmers to simulate sunrise & sunset External UL approval power supply with DC24V output to ensure safety operation Adjustable bracket for easy mounting on different size tanks, Removable parts, easy maintenance
18w - Best Suitable for 15" Aquarium Unibody design with whole aluminum housing, slim & exquisite looks, quite working Built-in controller with timmer & dimmers to simulate sunrise & sunset External UL approval power supply with DC24V output to ensure safety operation Adjustable bracket for easy mounting on different size tanks, Removable parts, easy maintenance