Description [Birthday Gift for Nurses andamp; Doctor, 4cm Ruler andamp; Pupil Gauge]Designed with pupil gauge and 4cm-ruler on the side of this penlight, which can help doctors or nurses measure the pupil dilation and length accurately and quickly when using medical pen lights, bring great convenience to the daily work of doctors or nurses. [Dual Light Sources andamp; Easy to Use]Freely select white or warm light mode as you need. Just push button forward for white light and push it back for warm light. Bright white light is great for checking nose, mouth, ears or as a flashlight for lighting in the dark. Soft warm light is perfect checking eyes. [USB Rechargeable Medical Pen Light]No more wasting money on buying batteries! Also no more messy cable! Mini LED penlights has built-in rechargeable battery, you can recharge by the USB charging port it at anytime via usb socket, power bank, computer, etc. Tiny blue indicator light show up when charging and it disappear when fully . Note: Please fully recharge this reusable LED pen lights before first use. [ Penlights with Pocket Clip andamp; Material]Weighing only 20g/0.7oz with metal pocket clip, Nursing pen lights are convenient to carry. Premium aluminum alloy material makes these led pen flashlights possible to be more and long-life using. [Pocket Size andamp; Protective Magnetic Tail Cap]This compact penlight comes with a magnetic pen cap that can prevent damage caused by falling. Mini pocket size, just take it anywhere you want at ease. color: Black Material: aluminum Package Contents: 3*Penlights 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 picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.