Venipuncture Vein Finder Infrared Vein Viewer USB Imaging Infrared Infrared Blood Vessel Lamp Transilluminator Product material: ABS Use battery: polymer battery 800MAH (about 8 hours of use) Product ruler: as picture Light source form: led mixed wavelength Switch mode: middle button (one on and one off) Working voltage: 5V plug-in or charging use Product color: black Product packaging: color box Quantity:1pc English instructions,1pcVascular lamp,Type-c power cord_x000D_ Step 1: Dim surrounding lights (dark room)for best results. Charging use:Connect device to charger;plug charger into power outlet, or connect USB cable with power bank or your PC. Wireless use: When the device is out of power, connect the device to the charger for charging,theindicator light is red whencharging,and blue light whenfully charged,you can use itwirelessly. Step2: -With the LED lights on the skin, press the switch button. Note:Try to not look directly at the light. Step3: -Place device in contact with the skin and apply light pressure. -Veins will appear as dark lines in the center of the LED ring. -Slowly slide device along the skin to follow veins. Note : Veins will not show if device is not directly touching the skin. Package includes: 1xUSB Infrared Vein Viewer Transilluminator Note: Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! _x000D_ _x000D_ _x000D_ _x000D_ _x000D_