DT Swiss Squorx nipples are awesome, they're basically a double-sided nipple with a male Torx on one end and a standard square drive on the other. This spoke wrench mates with the Torx end and requires the Torx end of the Squorx nipple to be on the hub side of the rim. Why Torx? It's less likely to round out, and anyone that has built with traditional aluminum spoke nipples knows how easy it is to round over the edges.
If you prefer to build your wheels, or already have a set, with the Squorx drive on the inside of the rim, see our other Squorx tool.