It may sound rather odd but the counterweights in this section are the oil that lubricates using most of the attached kit on your Tractors! If you try using a fully loaded Sprayer without a counterweight you will quickly grasp why they are very important kit!
The base game includes the following:
Determining which weight you need and that works best varies from tractor to tractor and attachment to attachment. You do not want to carry the heaviest if you do not need it, since you are paying to haul around that weight in fuel. Just saying.
For most attachments we have found that the SB1000 works universally well.