This Precision Lighting LK530-2 recessed double contact stationary lampholder is for use with T8 and T12 high output and very high output lamps. This Precision Lighting lampholder adheres to the strictest quality control and quality assurance procedures in the ballast and lamp industry. Each Precision Lighting product is tested under the toughest conditions and meticulously factory checked for defects in materials to reach you in perfect condition.