A tahkli is a little support spindle. They have the whorl down low; the shaft is steel (usually), sharp point on the bottom and flattened and shaped into a hook on top. The whorl is a metal disk, sometimes a coin or just a metal disk -- mine look bronze-ish.
I found a good photo of one (not mine) here:
http://www.flickr.com/photos/katdee/169308992/
