These A/C gauge replacement knobs are essential components for automotive air conditioning diagnostic equipment. Available as a convenient set of two in distinctive red and blue colors, these knobs provide easy identification and control of your gauge valves. The star-shaped design offers excellent grip and leverage, making it simple to adjust pressure readings during service and maintenance work. Each knob features a hollow center that fits securely onto standard gauge valve stems, including Harbor Freight A/C gauge sets and many other compatible models. The durable plastic construction withstands repeated use in professional shop environments, while the color-coded design helps technicians quickly identify hot and cold side connections. Installation is straightforward with a simple press-fit design that requires no tools. Measuring approximately 1.5 inches in diameter and 1.0 inch in height, these lightweight knobs are 3D printed for precision fit and reliable performance. Whether you're replacing worn knobs on existing equipment or upgrading your diagnostic tools, this pair provides the functionality and ease of use that automotive technicians need for efficient A/C system service. Be sure to check the inside diameter of the knobs to verify proper fit.