This flashlight was bought on Taobao. It's a mini flashlight with a diameter of 21mm, and it can clip onto most objects of similar size. I put a piece of soft rubber inside and secured it with a zip tie. It clips onto my hat very tightly, and it won't fall off even if I bump it. The light shines right in front of my face, which is perfect for working. My printer's feeding clamp broke, so the print quality is really poor.