Pfeiffer D1 synthetic diester based oil mechanical pump oil (sold here by the 0.5 liter bottles PN PK 005 881 -T) is quality mechanical vacuum pump oil for the ultimate performance of your Pfeiffer Rotary Vane pumps. Pfeiffer D1 Oil is specially prepared by Pfeiffer to meet the Rotary Vane exclusive specifications. This is High-quality synthetic diester based oil for standard applications to pump down air, inert, noble and slightly corrosive gases. Used for high operating temperatures up to max. 120 °C extremely low vapor pressure, achievable ultimate pressure < 5 · 10-2 hPa. We recommend that you change your vacuum pump oil at least every 3 months to prolong the life of your vacuum pump.