well, seems i can't make up my mind, so i need a bit of input. i was using a Bing high flow on my 21mm PHGB. i cut it and modified so it would clamp on to the carb. i liked it because it was a bit 'stealthy' but seemed small (although i could easily breath thru it) not opposed to a UNI either, just wanted to see what the consensus is. here is a pic of the filter i modded
!<a href="http://s46.photobucket.com/albums/f102/vwparts86/?action=view¤t=MOPEDCRANK005.jpg" target="_blank"><img src="http://i46.photobucket.com/albums/f102/vwparts86/MOPEDCRANK005.jpg" border="0" alt="Photobucket"></a>!