Battery kill switch

Does anyone have one laying around or know of where to pick one up locally for a reasonable price?

 

Thanks for the responses guys. I suppose I should have been a bit more specific. The switch needs to fit the criteria listed in the rockfalls raceway rules. From their website:

"Any car with a relocated battery must be equipped with a master electrical cutoff, capable of stopping all electrical functions including ignition (must shut the engine off, as well as fuel pumps, etc.). The switch must be located on the rear of the vehicle, with the "off" position clearly marked. If the switch is of a "push / pull" type, then "push" must be the motion that shuts off the switch, and plastic or "keyed" typed switches are prohibited."

So the northern tool one won't work. I will need to check out Oreillys or order one. I had my dates mixed up, so I am no longer in a big rush.