UPDATE: During one short ride on the road, the rear light fell off it's bracket and I lost it. I contacted the seller but there is only a 6 month warranty.
These lights are very handy - USB charged and very small so they're easy to store when you take them off the bike. Mounting and demounting the lights from the bike is very easy - you just pull a stretchy piece of material round the handle bar and clip it on.
Only disadvantage is that they aren't as bright as others on the road, but I suppose that's what you get for this mid-range price. They are good enough to use on well-lit streets so that other road users can see you. Definitely not suitable for trail biking.
Overall, I'm very pleased with the purchase.