The Accu-Gage Professional Tire Pressure Gauge has a fully geared, precision movement with bronze Bourdon tube. Unlike piston-plunger type gauges, the Bourdon tube movement is not affected by changes in temperature, humidity, or altitude. Flexible 11 inch hose between gauge and angled swivel chuck. Needle holds pressure reading until released. Push-button valve bleeds air to desire pressure. Protective rubber guard installed. Lifetime Warranty (USA and Canada).