Here is a video of the Berthoud 2000 Pro-Comfort knapsack [youtube=http://youtu.be/1IT1mqjpFU8]sprayer in use, showing the comfort back frame and strap assembly and sprayer operation.
Agratech Blog
The Crop Sprayer Expert
Here is a video of the Berthoud 2000 Pro-Comfort knapsack [youtube=http://youtu.be/1IT1mqjpFU8]sprayer in use, showing the comfort back frame and strap assembly and sprayer operation.