Review on Pieces Filter Retainer Compatible 5N11 by Yung Kaelin

These brackets attach to respirator cartridges but are easily deformed. Note that the pre-filter seals onto the cartridge such that this retainer applies even pressure to the pre-filter around the entire perimeter of the cartridge. This prevents a small air channel from escaping that bypasses the pre-filter. The main reason I'm giving this bad rating is that during use one of the brackets just popped out - I've been using 3M respirators with original parts for almost 10 years. and this was the first time the bracket broke off during use. Also note that 3M has a patent on the shape and size of the holder so these fakes must be slightly different in shape, size and material or they are just sold. illegal.