Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Don't waste your money...

Very inaccurate and will read level until you really tip them. They also get stuck in place and you have to tap them to get the ball moving. The adhesive is useless and when I went to screw them in they cracked under the lightest pressure. If they weren't so cheap, I would take the time to send them back. Now they are just headed for the trash and I have two holes in my trailer for nothing. :(