The O-125v2 is a premium charger level monitor/tester that measures voltage and confirms if the vehicle charging system is working correctly. The O-125v2 has Duo technology and is for 12V / 12.8V batteries. Features SAE to SAE connectors with rubber sealing cap & shroud to protect from dirt and liquid on charge connector. LED blink mode operation: LED will blink next to battery type to indicate sufficient voltage. Charge when LED below battery type blinks. Cable rating of 16AWG (1.31mm2) SPT-2W, -40°C/-40°F.