Robertson Worldwide warrants to the purchaser that this ballast will be free from defects in material or workmanship for a period of 2 years from date of manufacture when properly installed and under normal conditions of use. For more information on Robertson Worldwide's ballasts, call 1-800-323-5633 or visit www.robertsonww.com. For our energy star compliant ballasts, visit www.nema.org/lampballastmatrix/ Specifications subject to change without notice.