Original formula (Tuning Slide Oil). Medium viscosity for most first and third valve slides. Hetman® Synthetic Slide Oils are formulated for first and third valve slides (trumpets, cornets, etc.). These lubricants are designed to maintain an airtight seal and smooth slide action when making intonation adjustments. The proper choice of viscosity grade depends on the fit and length of your slides. Generally speaking, lighter viscosities are needed for tighter fitting and longer length slides, wher