I do not think there is a choice for length. Most of the extensions have two holes for setting the extension in the hitch receiver. The holes are a few inches from each other. This is the only adjustment I have ever seen. Choose the extension that keeps the tow bar level when connected to the toad and coach. The coach side can be up to 4" higher in a worst case situation. The coach side should never be lower than the base plate connection points to the tow bar.
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
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