Where to buy EKG calipers???

Any suggestions for a place other than a scrubs supply store where I can buy EKG calipers? I need some by Thursday and everywhere around here either doesn't carry them or is sold out...
Ive seen them at office supply stores.

wal mart. They should be in a school section; its called a Compass

med school or nursing school bookstore?

one of these http://www.amazon.com/General-Tools-...1722245&sr=8-1and I'm good to go?

I've used my old blueprint dividers They were expensive, and I am glad to still use them.

I bought mine on ebay, but there is a cheaper way. You can use a alcholol prep pad to do the same thing, just use the edge of the pad as one point and make a mark with pen or pencil on it for the other point. I keep plenty on me while on the floor. Quick, cheap, and easy!

I got mine at the local scrub store