The Reaper Rail Upper Assembly provides all the benefits of a ball head without the issues. The Reaper Rail Upper Assembly mounts with Arca Swiss rails to medium and heavy-duty tripods with 3/8-16 threaded studs or Arca Swiss mount. The rail's offset design allows you to easily remove magazines without obstruction. This patent-pending innovation eliminates the need for slight adjustments to the tripod if it is not level. The 11 degrees of rifle cant (left and right) gives users the opportunity to quickly level while setting up for those hasty shots in the field. The Reaper Rail Upper Assembly is a more compact alternative to the original Reaper Grip without losing stability.