From Brookstone. I pulled off the back drilled a hole and bolted a piece of velcro to the back. Using double sided carpet tape i added foam to the inside. The velcro needs something to compact and keep tension on it like squeezing the foam pipe insulation. It fits all 15 of my bikes. It's accurate, the pavement is always about 5-10 degrees hotter than on the grass. The shade is always about 5 less. I use it in 115 f to 10 f almost all the time.
I learned what to wear before leaving the house with this.