About Zoo Medical LabratoriesZoo Med is the number one company for reptile products worldwide. They introduced the first American reptile vitamin in 1982 and today hold 8 reptile product patents and 9 aquatic product patents in the USA and internationally with more pending. Zoo Med invented UVB lighting for reptiles, back in 1993 and which since has become the standard worldwide for Zoos, Veterinarians and the reptile hobbyist. A wide variety of products make up the Zoo Med family including quality products for reptiles, amphibians, fish and birds. Please note this product does not ship to Pennsylvania. Designed to fit terrariums 20 inches wide and up. Can hold one 18 -inch reptisun linear fluorescent lamp. Built-in reflector for deeper penetration of light. Reflector allows UVB into terrarium.