Magnetic Cat Door replacement key

This is a cat collar pendant that works with our magnet-activated cat door. You can buy replacements for about 5 bucks each plus shipping, or print your own for about a dollar each.

It is designed to captively contain two 1/4" dia. x 2/10" thick magnets. The print is paused at z-position ~12mm, the magnets are inserted, and the print is allowed to finish.

My source is K&J Magnetics, and this is the part number:

http://www.kjmagnetics.com/proddetail.asp?prod=D4H2

Note in one of the