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 its components completely cool.