LSE Lighting GPH436T5L/4 GPH436T5L/4P 20 watt 20W Germicidal UV Tube 4-pin Base 17.17" Brand: LSE Lighting Length: approx: 17 1/2" - Base Type: 4pin ONE END Effective Hours Rating: 10,000hrs Watts: 20W replacement for for Emperor Aquatics sterilizers and others.