Amazon so this is the lawnmower 5.0 Ultra and this is the lawnmower 4.0 and today we're actually going to go ahead and do a quick comparison of these two razors because there are some major changes between these two trimmers now first off from a design standpoint the 5.0 and the 4.0 they look and weigh very similar and they have a very similar shape to them as well however from a design standpoint the back of the 5.0 is a little wider than the back of the 4.0