RYOBI 40V Mower. I've been using this mower for a couple years to mow the ditch in the front yard. The mower works very well on flat surfus. There must be a switch that turns it off when it is not level or going over bumpy ground. So I turn it off and restart it (just push the start button).  I will be hiring my mowing next year and thought I'd get rid of this.