Back in the days, before bar end caps existed, cyclists would place a nickel between your handle bars and the hole in your grips. As a tribute release, and a sign of the times, Milwaukee Bicycle Company released the Nickel Bar End Caps. Simply put, you place the bar end cap on the end of your handlebars, and you would take the nickel and shove it in the bar end caps. Randomly selected nickels will be sent with every purchase of Milwaukee Bicycle Company Nickel Bar End Caps, and it is strongly suggested to super glue the nickel in so someone will not snatch it. Available at Milwaukee Bicycle Company for $11.99.
Source: Prolly is not Probably