You want hotlinks - I give you hotlinks:

http://www.acrartex.com/products/catalog/rescue-and-distress-lights/firefly3/

I didn't scrounge around for links to the 4F;I believe it is no longer in production, although there is a lively commerce in providing updated batteries (usually lithium rather than the original mercury battery).

The equivalent evidently is the firefly 3.

One thought about strobe lights carried for hiking and outdoor use. Chances are we will be more likely to deploy them for some travel incident relative to a hiking trip - indicating your presence while changing a tire on the side of the highway, for instance. I would be interested in the opinions of experts here on the forum - wouldn't a red filter be more appropriate for such highway related use? At close range,the white light of a Firefly 3 or a 4F is likely to be too disconcerting. Opinions?