Designers Edge L23 Cci L-23 Rough Service Halogen Lamp with Hard Case, 500 W, T3, 4000 Hr, 500-Watt Includes Bulb Buddy Case and (6) 500-Watt Halogen replacement Bulbs Rough Service bulb has 2x the lifespan as regular, 4000-hour rated life with heavy duty filament support The unbreakable plastic case is heavy duty Foam inserts in the case protect each bulb individually Halogen Bulbs have T-3 Shape, 4-5/8-inches long