The Rexroth R930006447 and R930006860 are premium block-type hydraulic counterbalance valves specifically engineered for heavy-duty mobile machinery, including rotary drilling rigs. These highly reliable valves function seamlessly as mast balance valves and slew (rotation) balance valves, ensuring precise load control, stability, and safety during demanding operations. Constructed from high-strength machined metal, the valve block features multiple threaded cartridge ports and secure port plug screws to withstand high-pressure hydraulic environments. Designed to exact OEM specifications, these genuine Bosch Rexroth valves guarantee durability and superior hydraulic performance in the field.