Carry emergency cash right on your keys! Have you ever left home without your wallet? How often do you leave home without a key? With the Cash-Can you will always have some spare cash, just in case! Is this a gift for someone special? Add personalization! 1 1/2 Inches Long 7/16 Inch Outer Diameter 3/8 Inch Inside Diameter Machined from Solid Brass Holds One Bill Be sure to check out our YouTube video on the best way to fold a bill... https://youtu.be/bpNnn6I4OsM (copy and paste this URL into your browser).