BASE CAMP M Plus or M Cross Valve COMBO PACK

This face mask is excellent for woodworking dust protection. The two strap arrangement is far superior to the paper medical masks that I have been using. The fit is tight yet comfortable. In addition the availability of replacementparts from Amazon is another advantage.

They work as designed

This item contains ONE single replacement outflow valve. Since each Base Camp mask has two outflow valves, if you want to replace both of them (or to have a complete pair of two spare valves), you must order a quantity of 2 items. The supplier now allows order quantities of up to 6 items. Order accordingly!Updated rating from 3 stars to 4, based on seller incentive of free replacement item. If seller wants 5 stars they will need to clarify the item description and photo which, likely inadvertantly, seem to indicate a 'set' of two valves for sale. More recent buyer reviews after mine continue to indicate confusion regarding this issue. I suggest seller use the paragraph above to clarify their ad, removing all use of the word "set." A new picture should show the separated inner and outer valve sections, otherwise it will continue to look like a nested "set" of 2 valves (which it is definitely not).This item comprises ONE complete valve, consisting of an inner and outer valve section (shown nested together in the photo). These two sections twist together after passing through the corresponding fabric filter and mask outflow holes. This assembly holds and protects a silicone diaphragm in place (4 included in item package) to form a single one-way (outflow) valve.Although the valve is not difficult to replace, there are no instructions included. Supplier pictures indicate that a single silicone diaphragm must first be mounted on the inner valve section, properly seated over its center post and oriented with its concentric ridges forming a slight outward facing-cone.The filter replacement procedure is also the basis for valve replacement, remembering that the inner valve section must be inserted first through the filter and mask outflow holes. Once in place, the outer valve section must be seated and turned a full 90 degrees clockwise to lock into the inner section.To direct outflow in a specific direction, the inner section slots must be correctly aligned relative to the mask prior to attaching the outer section. For example, if you want valve outflow to be directed downward, the inner valve section slots must be aligned vertically, and then the outer valve tabs seated so that the outflow guides appear to be facing forward. After full 90 degree clockwise rotation to lock, mask outflow will now be directed downward.Be safe and remember that masks with outflow valves do not provide source protection. They only protect the wearer from other sources. That means if the wearer is a possible source, this mask should probably not be a first choice. The wear of outlfow valve masks may be seen unfavorably by those who know the difference. My personal practice is to wear this mask with a fabric neck gaiter, which I can pull up to cover the valves in public.Very good form/fit/function.TL;DR: Buy 2 of these if you want a full set of valves for your mask.

Had a black gasket instead of the white one, feels a bit stiffer which I like.

Did not send the 4 Extra Diaphragms as Advertised... Very Disappointed.10/13/20: Very late update. I did receive the missing Diaphragms from Base CampA Couple Months ago.. and they also sent me and extra valve too.I appreciate the Persistence of Base Camp and Rep Melody to insure that I receivedAll that I purchased and more. Melody continued to Nicely remind me to update my Review of tge Purchase.Sorry so long Melody.. Coronavirus and other issues keep my life Super Busy. Thank you for your help and Patience.

When I bought this swore it said 6 piece set NOT 1 M valve filter,1 valve Filter cap and 4 rubber valves. Either it was a bait and switch or some how got mixed up with the other ones I was reviewing before buying. That said yeah it's nice but what I paid for doesn't add up just for 1 piece set price. Seen way cheaper for 20 for almost same price and I dont need that many. Seeing other reviews having a similar experience.

I am a wood worker and wanted something more than a paper mask. It fits well and works really well

First of all.. These are not the same vent design as what comes with a base camp mask.. This is not really a problem, but I do like things to match and only needed to replace one.Secondly.. These fit by being tight through the hole of the inner filter and the cap of the vent fits on that, instead of attaching to the mask itself and using an inner clip like the originals. I would much prefer the other design so I don't have to concern about wearing the fabric of the mask or losing a piece..Thirdly, and not entirely applicable to these vents.. Base camp actually glues the parts of their vents together on the part of the vent attached tot he mask itself so I had to carefully use some wire nippers to cut it away without damaging the fabric of the mask..It is however, nice to have both vents in working order again.. in spite of the above issues.. Thank you...

perfectly fit for my mask

Difficult to breath trough.