Real Feel Temp Sticks patent-pending products provide hitters and parents with the confidence needed to get the best performance possible and the most durability possible out of their baseball/softball bats! Factory warranty recommends that players do not use their bats below 60 degrees Fahrenheit or above 100 degrees Fahrenheit before either warming the bat up or cooling it down before use. With Real Feel Temp Sticks, you can trust that you are getting the best bat performance possible, getting the most durability, and staying within factory warranty recommendations!