Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Works good when it works...

This device does a good job when it is actually working. I have gotten used to pulling apart the motor assembly, cleaning it out, and putting it back together (you know it is time when it starts clicking loudly). You also get used to cleaning off the bottom of the pan because the device does not do it well enough even with premium clumping litter.I would not buy this product again.