1. Detachable head, easy to install batteries
2. The barrel is equipped with a scale and pupil size comparison chart
3. With pen clip, can be clipped in the pocket, collar and other places, easy to carry
4. Lightweight design, easy to use
5. Bright light, power saving, environmental protection, durable
6. Alloy button switch at the end, easy to operate.
7. Battery spring contact, using physical reverse technology, to prevent oxidation / poor contact and other phenomena
8. Material: aluminum alloy, resin
9. Power supply: 2 AAA batteries (not included)
10. Size: about 13.8 x 1.3cm
11. Weight: about 18.4g