Capsule type Stir Bar

It's a stir bar made to fit a 3/16" x .75" cylindrical magnet. I have a stack of four 3/16" x 3/16" magnets inside one. Great companion for my [stir plate](http://www.thingiverse.com/thing:447625/)!

Let me know if you want different size capsules, or to use different size magnets.