Tell them you are re-pinning a lock for a master key, or are an amateur locksmith, but somehow misplaced your depth key set. Try on-line sites for depth keys, or go to a locksmith or old-school, mom 'n pop hardware store. You can also probably find the specs on-line, and cut your own. Kwikset uses 6 distinct depths and Schlage uses 5 (IIRC), so use the deepest one. If you can get hold of one, you want to use a depth key. I know in California for example it's a crime just to possess them even if you haven't used them in an unlawful way. One more thing to keep in mind is that more and more states are passing laws prohibiting the sale and use of bump keys. is the most reliable site I know of, I'd suggest the "18 key" set, it's the one I own and it'll cover you for almost any lock you should happen across. The best place to buy ready made ones is on the internet. Some love it because they can create a level of hysteria and sell expensive locks to naive consumers claiming that they're "bump proof" when in reality they're anything but. It's hard to find a store that will actually sell bump keys, because most locksmiths are assholes who believe that all forms of lock bypass tools should be outlawed for everyone except certified locksmiths. The science is pretty straight forward, all the key really is is a conduit that transfers the horizontal force of your blow into a vertical force sending the pins shooting up into their cylinders simultaneously, and assuming you're applying some torque the second those pins hit the shear line the plug turns catching the pins. You also need to remember that you need a different key for every model of lock, and just because it's the same brand doesn't mean it's the same model of lock. It's fairly easy to make your own but if you have absolutely no idea what you're doing you can end up jamming the key inside of the lock requiring a locksmith to remove the key and open the lock. They do work great but it does require some practice (though not nearly as much as actually picking the lock).