It's good lasts a long time, the biggest design flaw is that there is a thin spring inside the rotary "piston" this spring will corrode if you do any kind of chemistry I had to open it up and remove the rusted spring which made it very loud but over time it settled in again and is working, this spring should be made of something non corroding or be sold separately/give a replacement in the box.
I have abused these pumps VERY hard HCL acid Nitric you name it thing is completely rusted from the inside occasionally i scrape the gunk out of it but it just keeps on going, and for 70 bucks I can afford to buy a replacement every year lol.