Flame King 30lb OPD Valve For Hog or Horizontal Propane CylinderFlame King Overfill Protection Valve helps prevent the 30LB propane tank overfills by closing when propane liquid level reaches to an 80% fill rate. Made of high quality premium materials for your safety UL Listed. This valve is compatible only with the 30 Pound Horizontal and HOG Propane Tank Cylinders by Flame King item #s YSN301HZL and YSN30HOG. Does NOT fit the vertical 30LB tank. IMPORTANT: The purchaser of this product assumes all responsibility