Manufactured to NFPA 395 specifications for farm and isolated construction use, tanks come with full-length boxed skids and lifting hook for easy movement of an empty tank. Standard skid tanks have five openings: fill, supply, level, operating vent and spare. The 2" standard size fill port for each tank may be changed to 4" by request. A 1" drain opening is standard. Depending on local codes, the 1" drain may be eliminated with no issues.