Husqvarna 596765901 4 Gallon Backpack Sprayer - Professional Garden & Lawn Chemical Applicator for Weed Control, Pest Spraying & Fertilizer Application

I live on 7 acres of mostly landscaped property. That means I need to use this often. The unit is fairly light. It's comfortable on my back. The listing says the unit itself is 12 pounds. I don't think so. That must be the entire unit, packaging and all. Still, remember, with 4 gallons of water based liquid, plus the weight of the unit, you'll be somewhere around 40 to 45 pounds when full. You can pump in more or less pressure to expand or narrow your spray pattern and it comes with several different spray heads that allow for a tighter, broader or adjustable pattern. I use two different types of herbicides in it, one for grasses and one for broad leaf. I rinse it three times when going between the two types. On the last rinse, I fill it half full, pump it up and spray out the hose with fresh water until it runs out of pressure. I usually do that twice and then dump the remaining water, and that seems to work to avoid damaging plants or grass. The orange top cap has a black rubber button in the middle. It's just a nub, but pressing it releases the last bit of pressure before you remove the cap. After my first full season of use, I'm really happy with mine.