Have you checked the company's website? If you browse around their products, maybe you'll be able to match it up. Or you can look up the one that's for sale and see what's on the website.
Xuron - http://www.xuron.com/
If you do a search on the forum (make sure you set the start date back more) for Xuron there were a couple of hits.
You might try reading this post:
Sprue Cutters / Nippers
http://www.finescale.com/fsm/community/forum/topic.asp?TOPIC_ID=356