Buyers must prioritize dimensional accuracy and material composition. Key specs include the spline count (typically 20, 24, or 28 teeth), the diameter of the base (usually 1/2" or 3/4"), and the total length. For high-performance applications, ensure the cartridge uses Grade A ceramic discs to prevent leaks and provide a smooth turning torque. Additionally, verify the maximum operating temperature (up to 90°C) and pressure rating (up to 10-12 bar) to ensure compatibility with high-pressure water systems.