This thing is worth the cost. It's extremely durable and passes the German shepard mutilation tests with flying colors it shines brighter than what I expected, and a few seconds under a uv light provides a bright glow that is one of a kind. The weight and slim design launch this frisbee further than any other disc I have ever thrown. My dog is very serious about his frolf discs. He sleeps with them in his mouth, and this one truly is a part of the family now. Don't waste your time with cheap alternatives. Understand what we are asking as a customer; a light up and functional disc so we can for some reason be out in the middle of the night throwing stuff into chained baskets. A very specific target audience indeed . And im never impressed with anything I buy these days. But the durability and the fact there's no cheesy battery's or cheap failing attempts at lighting, and the performance of this thing is quite impressive. The glow in the dark is mixed in with the plastic and it works flawlessly thank you for taking the time to make a quality product that surpassed my expectations greatly. And the quality of life that something like this brings to my dog and I is extremely appreciated I hope this product brings something special into peoples lives the way it did for me