Seasons Greetings etc

Gave my XM a $NZ300 xmas present in the form of a r/h top engine mount.(Old one sheared the top bolt out of the rubber)

Its a huge thing that appears to support the whole engine (weight wise) on that side by its lonesome.

It is also filled with fluid (old one was oozing stuff) but the fluid 'bladder'(?) doesn't come into contact with the car in any way. Amazing improvement in refinement (NVH) of the car.

My question is, why the fluid? Is it there to absorb a certain resonance / vibration perhaps? (a/c compessor?)

BTW the same unit (same part #) for a Pug (605) is $NZ60 more!

Have a good one chaps & chappettes.