Purpose: It can be used to check GDP-1 Portable Inclinometer, JGDX-3 Inclinometer, GDP-3A Portable Digital Inclinometer, and GDX-3A Digital Inclinometer at site. It can also be used to determine inclination of other projects on the ground. It can be used as a water level, too. It is portable. It is the tools to determine inclination at site. Technical parameters: 1. Measurement range: (1) Dip angle: 0°～90°; (2) Azimuth angle: 0°～360°; 2. Measurement error: (1) Dip angle: ±0.2° (the smallest reading is 0.1°); (2) Azimuth angle: ±2° (the smallest reading is 0.1°); 3. Instrument size: 280×100×120 mm; 4. Weight: 1 kg;