CTA Tools 3238 Spark Plug Gap Gauge - 9-Wire is designed to accurately measure spark plug gaps. The sizes range from 0.025, 0.030, 0.035, 0.040, 0.044, 0.045, .0.050, 0.055 and 0.060-inches. Heavy-duty construction allows for strength and durability. California Prop 65 - Warning, This product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm. Wide range of professional automotive specialy tools Professional grade Heavy duty design