NuckLJac is the modern approach to jack alignment. Made from stainless steel, this tool simplifies the task of jack to knuckle alignment, while eliminating the parallax view that occurs during this point of regulation.
Easy to use. Just clip the NuckLJac onto the top of the jack. While keeping the wippen in the "rest" position, align the side wings to meet the back of the neighboring knuckle core as your point of reference.