When I first started using the Roku Ultra, it froze from time to time. After scouring the internet to see what others have done to solve this problem, I bought a heatsink. The Roku is about the size of a sandwich and gets very hot. The radiator worked great and I don't remember a single freeze since I bought it. I am very satisfied with this product. It's a slightly larger surface for the Roku to sit on, but it's the only size that was larger than the Roku to allow it to lay flat to keep itsโฆ