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. penlights always comfortable touch in your hands. pen lights with bright white light perfectly help you to do daily work. 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 these pen lights durable and long-life using. It also comes with a pen cap to prevent damage caused by falling. Essential 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 helpful to measure the pupil dilation and length on using these penlights. color:Black Material:Stainless steel size:13.8 x 1.8m Package Contents: 1 x Pen light 1 x USB cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.