The 189970GS pressure washer pump is a robust component offering up to 3100 PSI and a flow rate of 2.3 GPM. This pump is suited for pressure washers with vertical shaft engines and features a 7/8" hollow shaft. It includes enhancements like a chemical injector and a thermal valve, and is pre-oil lubricated for better performance and durability. This pump model has been updated and is replaced by newer versions in some cases, so it's essential to ensure compatibility with your specific equipment model.