The first question to ask is, do you use your MTB on the trails or do you use it as a regular bike i.e. around town?
If you use it for off road biking and you only occasionally require light to see the path in front of you, I cannot offer you any lights for this. You'll need a high-powered battery operated super LED light.
If you on the other hand just like the look and feel of riding an MTB but you never really leave the tarmac, you could benefit from adding some of the lights below.extra weight is not a concern compared to your safety, you can basically mount all the lights you see in the "
They can all be installed if you follow the instructions, and they will make sure you will be seen at night.
If you have any questions, I'll be happy to help. Just send me a message or give me a call.