Compact rugged meter for non-destructive thickness measurements. The TKG150 is a Digital Ultrasonic Thickness Gauge/Data logger. Compact rugged meter for non-destructive thickness measurements. Extech offers Thickness Gauges designed in compact, handheld, rugged housing ideal for field use. The ultrasonic technology allows for non-destructive thickness measurements for primarily steel structures. Complete with protective holster, 2oz bottle of coolant, 2 AA batteries, 5MHz Transducer, hard carrying case, USB cable and Exporter software.