Love both of these super cool USB Rechargeable Bicycle lights! The rear light is red/blue flashing or solid, and it attaches to the underneath of the seat, and the front light is super bright, and it attaches anywhere on handlebars, you want to place it! Both lights attach easily and securely with hardware they come with and removes easily to take off when you need to recharge again! I have yet to have to recharge them but I have removed them, and replaced them, seeing how they work on both my bike and my daughter's bike! They are both definitely usable on different size bikes, and I am getting another set!! I highly recommend these lights, for all the bikes in your household, you could even take the front light, get some velcro, and attach it to your helmet! In saying all of this, I would also highly recommend just going ahead and purchasing more than one set of these, and at this great price, you could afford to!
This is just a really great purchase, excellent price, super sturdy, and waterproof, both back and front lights are nice and bright, the front light being super bright, and they hold a long-lasting charge!