United Scientific Overhead Projection Ripple Tank - Wave Physics Demonstration Equipment for Classroom & Science Lab Experiments

I hate to give this product a bad rating. The ripple tank would have worked great if it had all the parts. The tank was missing the double pin and two of the plane wave mirrors. We were unable to complete all of the experiments. For the price of the tank it would have been nice for it to contain all the accessories. With that being said they were more than accommodating in taking the product back. I would have even taken the missing accessories.Dead on arrival. The unit arrived and would not start. The power lights came on, but nothing I did could make it start vibrating or creating waves. Too bad; this looks like a nice unit. But it's an expensive paperweight if it does not work.We sold this to a customer and they loved it!