It was extremely difficult to put together without instructions but I looked on utube and found a good video. You definitely need someone who is strong and good with tools and 3D thinking as it doesn’t come with instructions and the bit that bolts to the wheelchair isn’t ladled well.You can’t attach it with the person in the wheelchair as far as I can see, but that could be because of the wheelchair I’m using, Once put together and set up correctly it is amazing and works really well, I just wish the connection bars were clamp on instead of push through it would be so much easier.I have looked into a second battery but found it very expensive it would be so much better if it was linked to this item. It’s good value as all the other ones are way more expensive but I think they would be easier to attach!It charges really well buy it doesn’t come with an English plug so I had to use a shaving plug I already had!I was amazed at how easy it was to get the tax back from the seller they were very helpful and emailed me personally to explain exactly what to do.All in all I am overall impressed if it had a few tweaks it would be 10/10, I think I give it an 8/10 because it is difficult to attach.