A Hammer Head that can be added to the 2010/11 (current) models of Ergo, Nomic or Quark.
Includes the two bolts required to fit it.
According to Petzl they are also retrofitable to older Nomics but only if you fit a 2010/11 Nomic Pick at the same time - however we disagree, at least unless you are prepared to do some bodging.
Weight of hammer head alone without nuts and bolts is 58g.