The timed impact of the Single Impulse (SI) design allows for low frequency vibration, reduced noise levels, and greater material control.  SI Series models are ideal for removal of powdered materials found in most dust collection hoppers and bag houses.  Essentially, the SI Series vibrator is a sledgehammer with both controlled intensity and controlled frequency.  Six sizes are available, and each can be converted in the field to a continuously impacting vibrator if needed.  SI Series vibrators require the use of a pneumatic or electronic timer and solenoid valve.