This very unconventional 39" Stick-Light exists because the inventor of this product is a professional mechanic and to fill in the gaps for those inspection and repair situations whereby any other work light will either not reach a deep secluded area like for example the top of a long fuel tank that is being lowered to replace a fuel pump (to prevent breaking a plastic vapor line that you cannot see) or to look and listen at the same time for where a noise is coming from by the belts and pulleys with the engine running or to illuminate just a really tight area that lacks good access points to illuminate a bolt you need to remove. Love this light when doing a GM LS power steering pump. I stand it up next to the pump and it is touching the ground while its 3600 lumens illuminates the hose attachments and bracket mount bolt with ease. This light also comes with a 6' power cable that allows attachment to the vehicle battery for a more lengthy repair power source and you can choose to add the portable M12 (or Dewalt 12V) battery housing with magnetic feet that can just impulsively hang almost anywhere there is a bit of ferrous metal. It should be understood though that the power consumption of this  39" 3600 lumen light stick is high and battery charge level will reduce quickly. Use it to power the 39" Light coupled with a 6.0 mAh M12 or DW battery and expect about 1 to 1-1/2 hours ~ of light. If you power the 39" off the vehicle battery for a couple hours, do not be surprised if the vehicle needs a jump start when you are ready to start it after your repair is finished. This light gets hot. Do not lay it on anything for long like a seat. When you have this light with the portable battery housing, there will be jobs that you do that you will know that this light is providing you a method and level of illumination that you just cannot achieve with any other light. And of course it comes with a pair of strong eyelet magnets that allow this light to easily be used as a standard hanging underhood light or any place under the body or side of the body while being powered off the vehicle battery using the included cable with alligator connect. No battery is supplied. You use your own battery. 
 
Reminder: The Dewalt battery platform is 12 volt not 20 volt.