Rola-Chem M-3000, Pool SentryCondition:* New Surplus Stock, In OEM Packaging. As Pictured.Additional Notes:*Maintains water level due to evaporation*No tools requiredsimply attach hose*Maintains set water level in pools or spas*Protects pool pump against burnout* Fills pool after acid wash* COMPLETELY PORTABLE!* Operational range 2 to 8 below pool deckRola-Chem M-3000