The Treiber K has the exact same composition as the TB Spirit/ALC, ZJK ALC, Viscaria, Yinhe V-14 (Pro?), Sanwei F3, TMount 540, Gewo Force ARC, XVT Dragon Face, Donic Ovtcharov TrueCarbon, Tibhar Drinkhall Powerspin Carbon.
All these blades have koto on layers 1 and 7, ALC on layers 2 and 6, limba on layers 3 and 5, and core layer (4) of kiri.
The Treiber Z has hinoki outers, and “Z-fiber” (Zylon/ZLF ? Or zylon-carbon weave, i.e. ZLC?) as its composite material. It’s a very different feeling blade. Its predecessor was called Zylon Kiso Hinoki, if I recall correctly. Some swear by it, others swear at it.