The behind-the-neck pull-down is a cable exercise intended to target the muscles of the upper and middle back. If you have the requisite shoulder mobility, it can help you targets the upper back muscles, including the trapezius and rhomboids, as well as the lats (latissimus dorsi). It is popular among elite bodybuilders and physique athletes, but some coaches consider it unsafe to the shoulder joint, in particular to people with existing shoulder problems.
Targets the rhomboids and lower trapezius, two important postural muscles
Can help build or preserve shoulder mobility, if you have adequate mobility to perform the movement
Constant tension throughout the movement, including at peak contraction
Can be done light for high reps or in traditional muscle-building (8-15) rep ranges