Feature: 1. 5 Sided Base: The digital display inclinometer has a 5 sided base for audible alarms over a settable range of angles. 2. Operation Procedure: There is a 4 sided V shaped housing for easy installation in corners or on pipes. Press the angle key on the first face, then rotate it slowly and the rotation shaft must be kept on the other test face. Once the unit is not moved, it will display the angle. 3. USB Connection: The digital level meter is rechargeable and it is very easy to use it by connecting the USB cable to the USB port of the device and the computer. 4. Port Type: The electrical port of the digital inclinometer is 5V 500mA for Mini type B USB port, practical and safe. 5. Wide Application: You can use the digital protractor in the following applications, such as interior decoration, building areas, plumbing, flooring and stairs, carpentry. Specification: Item Type: High Accuracy Level Material: ABS Plug: US plug 100-240V Battery: 3.7V Lithium ion battery x 1 Battery Capacity: 750mAh (Shipping with built in battery ) Accuracy: 0-20 : (0.1 ) 20-70: (0.2) 70-90: (0.1) Package List: 1 x Level 1 x Charging Adapter 1 x USB Cable 1 x Instruction Manual