The operator is not subjected to physical ‘jarring’ or and the non-impacting vibrator means low noise levels.
Both models are attached by vacuum (from built-in generators) to the wagon and the powerful pneumatic vibrator does the rest.
The Vac 40M uses manual switches to operate the vacuum (from the main airline), and the vibrator, independently.
The Vac 200/4T has a simple push button to switch on the vacuum generators, with a short delay time before the vibrator automatically starts. A second push button stops the whole system immediately.