Instruct: Classify Amazon reviews into positive or negative sentiment
Query: didn't work very long

This collar worked for my lab initially, so I actually ordered a second one for my much smaller corgi. The strap is very adjustable so it fit both dogs fine. Soon after I received my 2nd collar, the first one pretty much stopped working. It would make a click like it was going to spray but then wouldn't. This problem was solved on a few occasions by shaking the device, but within another week or so it was totally toast. The 2nd collar lasted about the same amount of time, 2 weeks. It worked great on my dogs when, well, it worked...but that was not very long. I would not spend money on this product again.