This venerable tool is a gypsy in the bicycle world. First offered by Delta as the "Spokey" 20yrs ago. Then available from DT as their house wrench. Sometimes available, sometimes hard to find.
The design is currently from German tool and accessory maker, Cyclus. Their plastic seems substantially more rigid and strong than Spokey. We carry the red, 3.2mm size (fits most higher end 14 and 15G nipples) and the black, 3.4mm size (fits the larger nipples often found on less expensive, Asian spokes).