Don't expect a vibrant spray of colors.
I am going to start with what this prism isn't. It isn't going to produce a shower of color all throughout your room. It isn't going to be that spectacular without a strong light source (no, your flashlight isn't going to enough...unless you have some high powered super flashlight).

Now, for what it is. This prism will show you (and your children) how light bends by doing several different experiments (just creative). If you have a good sunny spot you can set it in you will get a good rainbow as well, not a lot of them, but you will get color. Lastly, and probably the most consistent (and fun) use, the kaleidoscope effect is a lot of fun and you can take the time with your kids making many new patterns on light weight posterboard and seeing what happens.

For the price it is not a bad investment, but be warned. This is not the suncatchers you might remember from the 80's.

It's ok
I guess it's a good value for the price. It's just ok in our book, though. My son LOVED it for about a day. Maybe I expected more?

Not enough rainbows
This is a perfectly good, sturdy prism (it's been dropped a few times). I had a more multi-faceted crystal growing up which produced more rainbows until I lost it a few years ago. I thought the "bigger" rainbows from this prism would be of higher educational value, but my 5 year old was too young to appreciate it to any degree. I think he'd find more rainbows more fun.
Also - lack of sun has been a slight problem this winter!

Light Crystal Prism
It works great. I use it to spray colors on the wall. Light
Crystal Prism is recommended for teaching about the spectrum.