Don’t forget to lock your bike up.
These are great little items for keeping the thieves away. Thieves tend to pick the low hanging fruit when they can, so when they spot one of these on your bike, they know more work is involved, so they’re more likely to leave your bike alone. While you’re riding, just toss it in your pannier or tank bag, or attach it somewhere on your frame, like I do. At only about $20, they’re super cheap insurance!