These are outstanding filters for your respirator (I use them on my 6000 series model3M 6300 Half Facepiece Respirator - Facepiece Only - Large Size, Requires Filters or Cartridges ) and are a terrific value when compared to the damage to your lungs they prevent. I am a contractor and I use them often for work, but they are just as great in the shop, yard, house. Here is my review of the product based on my experience. Pros: * Effective - These really block the particulates. Whether used in the workshop for wood dust, blowing in attic insulation, or cleaning out the dusty old attic, these filters will protect your lungs. They are also effective in blocking nuisance levels of organic vapors: Good for using spray cans of paint on your old yard furniture certainly, but not to be used in a high concentration environment like a professional spray booth. They are perfect for welding or brazing, outside airless sprayer use, in the woodshop, etc. * Efficient - These P100 filters are rated at 99.97 percent efficient, so there really isn't anything that's going to get through. Certainly good enough for allergy sufferers working in the yard or around the house, these filters are also ideal for working in commercial or industrial environments. They have a large surface area that resists clogging over time and keeps the breathing easy. These are some of the most comfortable filters I've used. * Lightweight - These filters weigh next to nothing. If you've used P100 rated canister-style filters like I have, these lightweight filters will be a revelation. Unlike the heavy canister filters that begin to cause discomfort within an hour, these can be used all day with no problem. I've found that the tension straps on my 6000 series mask don't need to be nearly so tight to keep it in position because these lightweight filters don't try drag them mask off my face as the day wears on. * Color - Bright pink that just screams to everyone in sight that you are protected from the toxic environment all around. That's a good thing, right? OK, maybe not, but I've found that the bright color has two advantages: 1) you can tell in an instant and from a distance if your crew is in compliance with their breathing apparatus, and 2) it makes it easier to tell (other than by your breathing becoming difficult to indicate that your filter is clogged, which is already too late) that your filter is getting full or is clogged by foreign matter. I appreciate this visual indicator, as I've had a hard time in the past when light colored particulates have covered my white filter. But pink? The color may not be for everyone, but you'll learn to love it every time you think about what they're doing for your lungs... * Value - For P100-rated filters that last, are comfortable to used, and that can't be beat for protection, these represent a fair ripper of a bargain. * Durable - While not to be used in the rain, these are moisture resistant. I was skeptical until I was in a misty environment, and they still perform very well so long as they are not soaked. I've also had them catch on various branches and machinery and have been surprised how resistant they are to tears and damage. Cons: * Color - I'll admit the color may not be for everyone, but I've learned to love it. Bottom line: These are outstanding filters for an excellent value. I've never had a complaint when using them and have found them to be long lasting and very comfortable to use; when it comes to the protection they afford, they are second to none, in my opinion. Five stars for top rate protection and highly recommended.