Maytronics Dolphin DLX5 Wheel Tube Assembly (99955952 ASSY) littlegiant This version is especially useful This version is especially useful when the original setup depends on the PH301 15UP design and cannot be cleanly replaced with a different heater style and this Darlly cartridge is designed for compatible applications using the 6CH 502 reference Mobility related assemblies are important because wheel support and alignment directly affect how predictably the cleaner can travel across pool surfaces A properly selected Maytronics wheel tube assembly helps preserve original compatibility and contributes to smoother cleaner travel and more dependable coverage