As usual, Google won't retrieve the recent message.
However, to the original poster & anyone else thinking of replacing a soil vent pipe with one of these things, do a google search for the recent thread concerning the problems with our set up (search for zikki and soil vent.)
To summarise, if you are relying on a neighbours SVP and his manhole gets blocked up with 10Lb of rotting meat! The smells are unpleasant to say the least!
My advise would be don't do it!
My brother in law has very kindly just re instated the SVP at our place and it is now much more pleasant (anyone foolish enough to want to buy a nearly new AAV? Grahams charged him £40.00 for this one).
Only problem is he had to re-arrange some of the woodwork in the loft to get the pipe through and had to "treat" a piece of timber. Sometimes it smells as if the wind is blowing up from the Creosote mines!