Review on 🐸 INNOLIFE- 6Pcs Silicone Waterproof Super Frog LED Bicycle Bike Head Front Rear Light: Ultimate Visibility and Durability by Justin Cage

These are Chinese clones of the original Knog Beetle lamp. They come in sets of 6 and cost between $8 and $9. Usually 0-2 has bad switch at first, you can save other parts and battery. With care you can replace (regular) CR2032 batteries. They used to be pretty reliable when they worked at all, but out of the last 18 we've bought for team use, at least 8 have died in use. That's too high a bounce rate to carry around even if they were free.