Hydrostatic Transmission Fluid Engineered for Low Maintenance - HT-1000 | #406030 Ideal for heavy duty hydrostatic applications requiring maximum life and optimum anti-wear protection for the components of today's advanced hydrostatic drive systems. HT-1000 is an engineered hydrostatic transmission fluid exclusively from Parker. Item Information Parker's Hydrostatic Transmission Fluid HT-1000 is a synthetic transmission oil engineered to provide maximum durability and long life for heavy-duty hydrostatic drive systems. Ideal for environments that require superior thermal stability and a low maintenance, 1000-hour oil. Users benefit from cooler operations and lower operating temperatures, extended fluid life (and greener operations) plus super oxidation inhibition and excellent wear protection. All Parker HT Series transmission are factory filled with Parker's Hydrostatic Transmission Fluid HT-1000.