High Efficiency Pool Filter: High efficiency robotic cleaning filter that removes dirt and debris from the pool such as leaves, dust and diatoms. It will make your pool spotless. Premium Quality: ABS plastic frame, more durable. At the same time, it can firmly support the filter layer and prevent it from breaking during operation. Recommendation: Washable and reusable, these filters can last 2 to 3 years if used correctly. Rinse the filter every 4 to 6 weeks for best performance. Compatible with: for Dolphin M400, M500. Same model 9991432-R4. The size is measured manually, please allow the error (1-3 cm) Due to the different monitor pixels, there may be color difference, please refer to the actual product. After receiving the package, if you have any dissatisfaction, please contact me first, do not leave negative feedback easily, thank you and have a nice day.