I bought my stir plate from my local shop. Since buying it I've replaced about 3 stir bars after loosing one or two while cleaning out the conicals. The other one just got away from me. To this day I have no idea where it ended up. Anyhow, I love my stir plate. Just be careful and don't beat the snot out of your yeast when using one. Yes they are very handy and contribute a great deal, but you can over do it. A representative from wyeast recommended 18 hours tops on the stir plate. If you are not brewing at the end of that 18 hours then decant off the liquid and place the starter in the fridge until brew day. Also use aluminum foil on top of your flask or beaker in place of an air lock. The idea of the stir plate is to get oxygen into solution. It's kind of counter productive to put an air lock on when using a stir plate. Have fun it's a new adventure into the world of brewing gadgetry.