When selecting emergency light bars or beacons, prioritize SAE J845 Class 1 certification for primary emergency vehicles to ensure maximum visibility. You must verify the lumen output and flash patterns, ensuring the equipment supports at least 10-30 selectable patterns for different tactical scenarios. Additionally, check the IP67 or IP69K waterproof rating to guarantee performance in extreme weather conditions, and ensure the housing is made of UV-stabilized polycarbonate to prevent lens yellowing over time.