He is talking about this one. not sure if it is still available. Try going to the link below and calling them for more info about a nickel radius.
You may just have to get the regular nickel Willard and carry both.
Willard's Universal Tool Champ is quite versatile as a tip shaper and knurled to file and scuff your tips. It's portable and convenient, allowing you to reshape your tip anytime. The gauge on the sides will show you when your cue tip is perfectly round.