Defensisve facemask for baseball/softball infielders.
Just did an informative speech on the speed of the ball coming off of the bat (and a picture of my daughter after she got nailed in the head).
There's awesome info out there. I didn't keep my sources but I do have this - maybe you can google a little:
Webusers.npl.illinois.edu
Daniel A. Russell, Ph.D.Applied Physics, Kettering University
