I bought a Lee Valley Large Clock Insert and I’m less than wild about it. Lee Valley is, as most people will rave, a great seller. But this particular product was lackluster: the mounting ring was difficult for me to fit, the lens is hyper-reflective, making it difficult to read the clock, and it weren’t exactly what I call inexpensive. Perhaps others have a different take on it, but I suspect the mounting mechanism that Klockit uses is easier to work with.