Pac Fab / Purex 61-4503, 61 4053, 500 Watt 120 Volt, R40 Light Pool/Spa Flood Lamp Bulb Bulb replacement Only Fits Underwater lights Pac Fab / Purex 61-4503, 61 4503 , 614503 Quality replacement at 25% of the cost Thicker filament and glass helps withstand heat. Multi-filament supports resist vibration, internal heat shield prevents separation, heat resistant cement assures no loose bases, brass base resists corrosion.