Stuck it on top of the radiator on my YZ450F so I can peak over the plastic and glance at the color. The color coding is nice - green in the middle=all is well. Gives me an idea of what the temperature of my coolant is - it's just a general guide since the heat has to be absorbed through the radiator then into the sticker. Make sure to clean the aluminum with an alcohol or similar product before you stick it. I used brake cleaner on a rag. Holds well, no problems.