Not sure of longevity- but pressure seals well. I should have got two gallon. Dials work, sprayer works. Has annoying lock that triggers easy- causes me to overspray a lot, but solid construction.
This is exactly what they say it is and i like stainless steal for this application. Much better than plastic sprayers. They don't hold up. I don't expect I will ever need another because this appears to be a life time product !