The Bontrager Glo/Ember or Lezyne Femto are good ‘be-seen’ options. Both are powered by watch batteries, have solid and flash modes, are easy to take on and off with rubber straps, and small enough to fit in a pocket.
If you’re looking for something brighter, go for the battery powered Bontrager Ion1 / Flare1, or the USB rechargeable Lezyne Zecto Drive.
Unconditional Bontrager Guarantee - all Bontrager lights come with a 30-day trial period, if you don’t like it, return it for a no-quibble refund.
Brightness / Run Time Details:
Bontrager Glo / Ember:
front: 40 hours @ 5 lumens
rear: 45 hours @ 35 lumens
Bontrager Ion1 / Flare1
front: 50 hours @ 15 lumens
rear: 80 hours @ 8 lumens
Lezyne Femto Drive
front: 15 lumen flash, pulse or solid / 30-60 hours
rear: 7 lumen flash, pulse or solid / 30-60 hours
Lezyne Zecto Drive
front: up to 120 lumen flash or solid / 3-5 hours
rear: up to 10 lumen flash or solid / 2.75-4.25 hours