The Digital Drum Gauge by ATD is a high-quality automotive tool designed for precision drum measurements. With the manufacturer part number ATD-8658, this gauge offers accurate readings for automotive drums, ensuring optimal performance and safety on the road. Its digital display makes it easy to read and understand, making it a reliable tool. Graduated in .001″/.01mm increments Range: 4″-20.65″ (150mm-515mm) Stainless steel Easy to read digital display with SAE/Metric conversion Selectable depth stops for easier use Measure automotive and heavy-duty drums Pointed anvils and 4.25″ long arms to inspect drums before turning or replacing Powered by (1) SR44/357 battery