The buoyancy compensator must fit the diver comfortably and must stay securely in place without constraining the diver's freedom of movement. There is some conflict between allowing easy adjustment to fit a range of diver builds, and setting up the harness to optimum fit for a specific diver in a specific diving suit. This is a particular problem with jacket style BCDs which are inherently less adjustable for fit than backplate harnesses, which are more adjustable, but take more time to adjust.