Yes they do.  I have one.  You have to have a special lid that goes over the jar lid (they have wide and regular) and then there is a little tube that plugs into the top of the food saver that is connected to the sealing lid.  Then you just push the seal button like you would if you were sealing a bag.  Of course this is not a proper canning method, but it is great tool for sealing dry good into jars!  I even seal my lettuce into a mason jar and store it in the fridge and it lasts way longer!