Ready to use - includes both fixture and bulb Trim, compact design perfect for tight spaces UV fluorescent bulb delivers healthy full spectrum light A one-stop solution for terrarium lightingSimply set a Tropical 25 fixture atop a terrarium's screen cover to brighten a reptile's world with healthy UV illumination. The fixture is sturdy aluminum in a sleek designer black with a highly polished reflector, ideal for terrariums in tight spaces. The fixture is equipped with a bulb designed to deliver the 25 microwatts of UVB output at 12" that promotes calcium absorption and brings out a reptile's natural coloration. Great for plants too. CUL rated for safety. For greater convenience, add an R-Zilla Power Center to automatically match your pet's day-night life cycle (sold separately.)SIZE- 20 INCH SINGLE / DIMENSIONS- L27.50 W2.75 H1.37