This pen light can switch between white light and warm light modes according to your needs. The white light is suitable for checking nose, mouth, ears or as a flashlight for lighting, the warm light is suitable for checking eyes. pen lights are made of premium material, making sure these pen lights and long-life using. It also comes with a pen cap to prevent damage caused by falling. This pen light is designed with a built-in rechargeable battery. We equipped with the newest type-C to USB charging cable and you can charge the pen light at any time via power bank, computer, etc. Very handy penlights always provide comfortable touch feeling in your hands.Awesome pen lights with bright white light perfectly help you to do daily work. Essential handy light to check your children's sore throats, ears or noses.There are pupil gauge and a 5cm-ruler on the side of the penlight. It is very helpful to measure the pupil dilation and length on using these penlights.