Twin Air Filter# 158046
http://www.twinairusa.com/2007%20Twin%20Air.pdf
Moose lists :
PPO Pre-Oiled Filters 1/25/07bcl
MAKE/MODEL/YEAR PART #
GAS GAS
125/200/250/300 97-07 1011-0828
http://www.mooseracing.com/pdf/airfilterspreoiled.pdf
or
AIR FILTERS
3/28/07bcl
MAKE/MODEL/YEAR PART #
GAS GAS
125/200/250/300 97-07 M761-20-43
http://www.mooseracing.com/pdf/airfilters.pdf