Compatible with Sundance Spas hot tub water cleaner systems 2012 and newer, including J-200, J-300, J-400, and J-LX series. Also compatible with part numbers: 6472-841, 6472-857, 3LRK, 94-1552, UVL-3LRK-1. Backward compatible with older models. Package includes 2 pool and spa bulbs. For optimal performance, it is recommended to replace the bulb annually to help reduce maintenance costs. Easy to install: Remove the screws, enclosure cover, and gasket, then slide the replacement bulb into the quartz tube. Color: in image. Material: Glass. Package contents: 2 x Pool and Spa Bulbs. Note: The package includes only the items listed. Other products are not included. Light reflection and differences in display screens may cause slight variations in color compared to the actual product. Measurement may vary by +/- 1-3 cm.