I previously had a Mega which worked  a couple years. This one was a Total Disaster. Never could get rake to work, Littermaid customer service (once you finally get to is) was of little help and Orange Onion (don't buy anything from them) sucked. They couldn't care less, at least Littermaid apologized (on one of my three calls). Keep in mind, if you buy it and return it, do it through Littermaid. You only need to send back the battery cover and that blasted pull wire. To get that out ( NO help from Littermaid!), unscrew every single screw and once you get your hands on that wire, don't let it go! Or you have to take out the rest of the screws by the battery compartment. I wasted hours and hours on this. If only they had a good competitor. They're sending me the only thing available, the latest model that most people here seem to hate. sigh..if it doesn't work, I'm giving up totally on Littermaid. I have two cats, so it had its uses.