Product and seller deserve ZERO stars!
I own 4 different dust masks that I keep on/in various mowers/tractors on a ranch, and I’ve replaced the filtration-bypass valves in the past with other products that fit and worked perfectly, but these DO NOT WORK because they won’t fit, as others have stated in the numerous one star reviews for this lousy product.<br /><br />Additionally, shipping from China took two months for this garbage to get here.
Rating: 1 stars