HP 865408-B21, 866729-001, is designed to allow for hot-plug and easy installation into HP ProLiant Gen10 Performance Servers. HP Flex Slot Power Supplies are certified for high-efficiency operation with flexibility to reduce overall energy consumption as well as power waste. HP 865408-B21 500W Power Supply is compatible with DL360, DL380, DL385, ML350 Gen10 Servers.