Neptune Replacement DOS Head Cap Neptune Replacement DOS Head Cap is a replacement head cap for the Neptune DOS dosing system, sold individually for servicing one DOS pump head. Replacement Cap for Neptune DOS This part is used when the head cap on a Neptune DOS dosing pump is worn, damaged, missing, or needs to be replaced during service. It helps restore the pump head assembly without replacing the entire DOS unit. Head Cap Features Replacement head cap for Neptune DOS dosing systems Sold individually Useful for maintenance and repair of one DOS pump head Helps keep the DOS head assembly properly secured Compatibility Notes This replacement part is for Neptune DOS dosing systems. It is not a complete dosing pump head and does not include a DOS pump, motor, reservoir, or dosing tubing unless separately stated. Directions Power down the DOS before service, remove the worn or damaged head cap, install the replacement cap, then prime and test the dosing head before returning it to normal operation. What's Included One Neptune Replacement DOS Head Cap