SeaSucker Plugs Thru-Axle Adaptor Wheel Holder – 12mm. SeaSucker Wheel Holders are made to fit Bomber and Mini Bomber bike racks just swap the Add-On Front Wheel Holder for one of the fork mounts and now your front wheel doesnt have to ride in the trunk anymore. Elongated entry slots for the skewer allow the wheel to rest on the platform of the rack providing additional stability when driving. Made for standard road cross disc and MTB wheels.