I work for a major pest control company and have over 30 years experience in the industry. My company has recently switched from power spray units to backpack sprayer units for exterior applications.The company provided solo units that do not have adequate shoulder padding, support and after a day of 6 or more applications my back was killing me. I decided to buy my own unit and when I found your site decided to buy the 61900 model based on the features listed, mainly shoulder straps and padding. I am extremely pleased with my sprayer.  As soon as I strapped it on I felt the difference. The back padding, waist buckle, shoulder padding and shoulder buckle make all the difference in relieving back stress. I like the spraying features of the 61900 also. Pressure gauge, length of hose, sprayer wand, and adjustable tip. All in all an excellent sprayer .

Received the Chapin 61900 in a very timely manner. As a precautionary measure, I filled it with water and allowed it to sit for a few hours. Upon inspection, I found that it had a significant leak around the bottom flange clamp. I tightened and retightened the clamp several times until there was no further room to tighten. Still, the leak persisted. I then called the factory and spoke with Linda in customer service. She advised me to follow the instructions in the manual and to disassemble the unit, a task that I found very easy. Upon disassembly and inspection, I found that the bottom "O" ring had been pinched by the plastic reservoir body during assembly. I applied copious amounts of petroleum jelly to all parts and reassembled the unit. No leaks. I called Linda again and advised that the unit was not leaking, but was likely going to leak due to the pinched "O" ring. She made certain that she understood which ring was problematic. She then sent me an entire repair kit with all gaskets, "O" rings and other miscellaneous parts that might be required in the future. So far, no additional leaks. The unit works as advertised. Good, quick service after the sale. I would purchase another Chapin unit.

I have used this sprayer twice for weed control (received it two weeks ago) and am very satisfied so far--it is easy to use, appears well constructed, and not hard on the back. I would recommend it to anyone considering a backpack sprayer.