Buyers must prioritize Rated Voltage (kV) and Rated Current (A) to ensure compatibility with the power grid. Crucially, the Short-Circuit Breaking Capacity (kA) must exceed the maximum potential fault current of the installation site. Additionally, verify the Insulation Medium (e.g., SF6 gas, Vacuum, or Air), as this dictates maintenance requirements and environmental footprints. For outdoor applications, ensure a high IP Rating (IP65 or above) and Creepage Distance to prevent flashovers in polluted environments.