The Wiper | Rotary Transmission Shaft Key (VKL/VKS) is the OEM rotating shaft assembly that transmits motor torque to the wiper basket inside the evaporator body on VKS 95 and VK 100 wiped-film distillation systems. Manufactured to precise tolerances, it ensures smooth, concentric rotation of the wiper system while maintaining vacuum integrity at the rotating shaft seal. An OEM VTA replacement part; replace during major overhauls or when vibration or seal leakage is detected.