Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great rock tumbler that will last for years

We bought this for our 10yr old daughter and she loves it. It's been a great activity for us to do together and the whole family enjoys finding good rocks to polish and gathering around to examine the changes in rocks with each changing of grit/polish.Rocks are free and grit can be found cheap and only needs to be bought about once a month, so after the initial expense of the tumbler, this is an inexpensive, educational and fun hobby.I had the exact same model when I was her age (25 years ago) and used it for a good 10 years before it got lost in a move. Keep it clean, dry, and put a drop of oil (3-in-1 works well) on the motor bearings before starting a new batch of rocks and this machine will last for many years.