Test batteries on or off vehicles quickly. Reliably test batteries and alternators and test charging systems ability, up to 100 amp loading capability.Safety switch prevents sparking. Heavy duty plated clamps.Suitable for most 12-volt car/van lead acid batteries. Suitable for all 12V Lead/Acid batteries and alternators and test charging systems ability.Tests up to 100amps. Safety switch prevents sparking. Heavy duty plated clamps.