MUA Mask vs. OM14 mask

[Crit20]

I am looking to buy a mask. I have the option of buying an OM14 or an MUA. The main difference that I can see is that the MUA has a valve thing over the nose, while the OM14 does not. What is the real difference there, and which is better?

[Tomasz70]

They are almost the same as regards construction and apperance - the main difference was the sonic device in MUA, allowing for voice communication. So, if you wish to use it and talk to someone, the answer is rather simple...