How to measure a brake drum using a brake drum micrometer. - YouTube
Manual Drum Measuring Gauge (Vernier) - Autogem
WHEEL CONNECT Brake Lining Thickness Gauge, Measuring Tool for Both Disc and Drum Brake Pads, Made of Steel, 3 Color-Coated, with Hanging Tag. : Amazon.co.uk: Automotive
CHICIRIS Digital Tire Tread Gauge Kit Color Coded Depth Measurement Tool Handheld Portable for Car Truck Disc Drum Brake Pads Wheel Parts : Amazon.co.uk: Automotive