Standard issue armament for Wulfenbach clanks is a heavy machine cannon colloquially referred to by other Wulfenbach forces as a Clank Gun. They have also been seen using longswords ("longsword" relative to them, they'd be really big twohanders to a regular human) as seen .
Bizarrely — to our mass-production-informed sensibilities — each appears to be unique. (They do all wear those tall parade hats with the feathers in front. "The taller, the better, so - Big Hat.")
In Agatha H and the Airship City Agatha observes that they move with a kind of animal fluidity and grace, showing they are far more advanced and top of the line then older models like the Watch.
The Works contains a number of each of cards titled Wulfenbach Clank 1 and Wulfenbach Clank 2. Both kinds (unlike what appears to be the case in the comic, the cards are not all unique) have Machine and Soldier as their detail epithets. The first is brass colored and is firing a red clank gun to our right; the second is steel gray and carrying a blue clank gun over its right shoulder.
Secret Blueprints, Vol. IEdit
Page 14 notes that "[t]he development of the perfect clank is an ongoing rivalry among the Gifted..." and "[t]he clanks built by Klaus Wulfenbach have so far proven superior to every other type currently being used...".