Weight distribution bars

Hi, selling my TT and looking for some input. My sale includes hitch weight distrubtion bars, and anti sway bar. The prospective buyer, was asking about details on the weight distribution bars and that I should have details on that. Says they need to be adjusted per vehicle. I bought my mine new, and they put them on. What adjustments are needed? I know mine go on the 4th link of the chain. What else would be needed other than if they have a higher truck, maybe it's three links or five links if smaller?

Made it sound like this was a big deal..how big of deal is it?

Thanks in advance.