I believe this is an old VAR tool. No longer made, although they show up from time to time. It has a lockring pick on the end with the cog chain wrap, and the other end has both hub nut and pedal threads. It was stamped metal and not very good on your pedals, and the pick didn't grab lockrings very well.
The one from EAI is limited because it doesn't connect properly on a reasonably wide range of cogs. It can scrape up a steel cog if you're not careful and if you use an aluminum cog, it can shear the point right off. The rest is an OK casting but not great. Personally, when I'm doing mechanic at the track, I have a stubby SnapOn ratchet with the appropriate socket that works just great. And I have a pair of VAR lockring pliers (from www.businesscycles.com
) that is the best way to handle lockrings -- it works on the toughest ring and on all the weird ones that other wrenches don't fit. The lockring pliers are thin enough that you can usually get the lockring off without taking the wheel off the frame; then kick the pedal hard with a backpedal and let the bike chain loosen the cog. There's also those Park pin tools that are not much more than a piece of bent wire -- they work really well for all but the worst lockrings and are the best for a messenger bag repair. I did find a neat thin chain tool that slides into a piece of 1-1/4" PVC pipe; with a glued-on PVC cap on the bottom and a loop on the top to hang on a belt or keep it upright in a tool bag, it keeps oil from cogs from getting on other stuff.