[Steering & Suspension] Steering Boot

[Multispacer]

I noticed one of my steering boots has torn at the inner end. I ordered a new replacement [made by Meyle] and what I received, although the same size doesn't have a breather outlet on it. Checking on both the Meyle website and speaking to autofactors I ordered it from, they checked even on the Citroen site and the compatibility is shown as what I've ordered [which has come up without the breather] I'm just wondering what is the breather actually for [the two opposite side bellows are connected together via a thin plastic pipe] and will it matter if I fit one side without the breather? I can send it back, no problem but I will have to source another with a breather from elsewhere and I was hoping to do the job on my shift rest days which started today, as my MOT is due in about 10 days time. Picture of the breather I am referring to below