These lights are good value for money, I would say the build quality is good, certainly not 5 stars. They attach easily to your bike, the rear light has a rubber bracket with a stretch loop to fasten around seatpost. The angle can be adjusted with a small screwdriver once you slide back a piece of rubber. The rear light is surprisingly bright, but the front light has two leds which are adequate to be seen by others. I did like the timing/speed of the front flashing mode - it’s not so fast that it becomes irritating. Many lights are almost a strobe effect. Both are rechargeable with cables provided. Charge time is about 2 hours. Overall I would say I’m impressed with this set, you get what you pay for.