SXF FC 250-450 23-24 MCF 250-450 24 Twin Air Powerflow Kit. 
The best filter in the world can’t do its job if there are leaks in the seal of the airbox. Twin Air’s PowerFlow Kits ensure a leak-proof, fool-proof fit with a rigid, lightweight, billet-aluminum cage that replaces your flimsy, plastic stock cage, and a billet aluminum flange with a rubber seal that bolts tight to your airbox.
GAS GAS MX
MC250F 24-
MC350F 24-
MC450F 24-
GAS GAS ENDURO
EC250F 24-
EC350F 24-
EC450F 24-
EC500F 24-
GAS GAS XC
EX250F 24-
EX350F 24-
EX450F 24-
KTM MX
250 SX-F 23-24
350 SX-F 23-24
450 SX-F 23-24
KTM ENDURO
250 EXC-F 24-
350 EXC-F 24-
450 EXC-F 24-
500 EXC-F 24-
HUSQVARNA MX
FC 250 23-24
FC 350 23-24
FC 450 23-24
HUSQVARNA ENDURO
FE 250 24-
FE 350 24-
FE 450 24-
FE 501 24-
HUSQVARNA XC
FX 350 23-24
FX 450 23-24