Standard Nipple – N Series Fumoto's N series Oil Drain Valves are specifically designed for cars, trucks, heavy duty construction equipment, and industrial engines. Ideal for fleet maintenance, N series valves are designed with an integrated nipple for attaching a drainage hose, making scheduled oil changes easier, faster, and cleaner. Constructed of forged brass and stainless steel to exacting Japanese specifications, N series valves are designed to a lifetime of dependable and reliable service.