Ok in that picture the side showing is the top of the weight.
The rounded recessed part is the part that the nut sits in. The other side has 2 recessed rounded parts where the orings go so the weight doesnt bounce around. If you look at the weight one side is angled down that goes towards the front of the car. Depending on what chassis you have and how you have your belts dictates where you mount it to the chassis, It goes right in front of the motor mount there are 2 holes. The battery "stopper" should fit into the cut out part of the mount.
I Know this is probably jibberish but if you use what I wrote you can kinda see what im talking about.
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