Won't it drip oil onto the exhaust manifold, if you attach it directly to the crank case.
Thus causing stinky oil burning smell
now i remember ; to fit it over the tube , the filter itself fitted perfectly without the adapter pieces . 25mm to fit it over the pipe, little too big but when tightening it's perfect
http://www.astuning.nl/Webwinkel-Product-704648/Mini-filter-voor-carterontluchting.html