The BlueSpot Brake Pad Thickness Gauge is ideal for the quick and easy confirmation of the road worthiness of brake pads. The offset gauge is inserted between brake disc and pad, the blade which sits most snug is indicative of the wear on the pad. The set includes three colours which denote the wear. Red: Pad must be replaced immediately; Yellow: Pad is becoming worn; Green: Pad is in good working order. The gauges are additionally marked with the metric conversion for the offset; Red:2 & 3mm; Yellow: 4, 5 & 6mm; Green: 8, 10 & 12mm.