The flange adapter allows the use of both 300mm and 315mm ducting/fans.
The step-up configuration is 315mm in diameter at it's widest point, and 300mm nearer the top.
The fan collar can be used if you have odd sized fans or ducting.
to suit 180 silencer
The plastic GT poly filter flanges are easily interchanged by twisting and locking.
Suits all Can-Filter GT range (poly) filters.