I have bought a couple of these and for the price you can’t beat it. I use them for automatic chicken doors so they are outside 24/7 and not covered from the rain entirely. They have lasted an extremely long time considering the abuse. I bought a back up one just in case one breaks one of these days but it’s still on the shelf due to the endurance of the product. I’m sure if you covered them and took care of them properly they might last for years and years. They can lift a good amount of weight and I was kinda surprised by overall strength of the device. I’m sure the more weight you lift that might affect the lifetime of it but I’ve had nothing but good experience with these so far. Mine go up and down 2 times a day in case anyone was wondering and do so with about 30 pounds of weight with ease. I use one to lift the chicken feed off the ground to protect from pests and other uninvited guests at night as well.
Paul Martiniano 
