Replacement window winder cable, mk1 MX-5, long cable that lowers the window. 

Note that it is advisable to replace both cables when fixing your broken window mechanism. 

Also available is the plastic drum that goes in the electric window motor for the cables to wind around.  This tends to get chewed up when a cable breaks.

Replacement instructions are here: http://www.miata.net/garage/window.html

Genuine Mazda part.

NM00272. NAY1585Y0.