Cocking devises will cock the XBow for you, and in doing so they keep cocking the bow even, if you tried to cock by hand you could be off a little bit to one side or another...the cocking device eliminates that, keeping everything lined up during the cocking process. Good idea to have it on a 200# or a 225#. Another way is rope cockers, theyjust reduce the cocking procedeure by about 50%, I have both...have never attempted to cock my 225# by hand yet.