This is Oerlikon Leybold Leybonol LVO220. This is quality mechanical vacuum pump oil for the ultimate performance of your vacuum pumps. Very high thermal, oxidative and chemical stability, good deterging and dispersion characteristics, excellent wear protection. Leybonol LVO220 is a Synthetic Ester Oil especially blended for use for RUVAC (WSLF) Pumps for operation with gas lasers. Optimized for use in Oerlikon Leybold Ruvac Roots Pumps. We recommend that you change your vacuum pump oil at least every 3 months to prolong the life of your vacuum pump.