It's a counterweight. It was heavy, but not as heavy as some.... I mean it's a weight, so I guess you expect that. It has a hole in it, like a doughnut, but don't try to eat it. I now need to see a dentist!!

In all seriousness, it does the job, original item, no complaints - now I can view the universe.

I use an extension bar including this 2kg weight for my CEM25P mount and it helped me achieve balance with a large Bresser Messier AR-127L telescope (8kg).