PR01 Series 1W, Axial Vishay PR01 series are high temperature metal film resistors with a high grade ceramic body. The resistors are coated with a red, non-flammable lacquer which provides electrical, mechanical and climatic protection. Vishay PR01 series are high temperature metal film resistors with a high grade ceramic body. The resistors are coated with a red, non-flammable lacquer which provides electrical, mechanical and climatic protection.