Incur, create, assume or suffer to exist any Lien on any of its property or assets, whether now owned or hereinafter acquired except for (a) Liens for taxes not yet due or which are being contested in good faith by appropriate proceedings;  (b) non-consensual Liens arising by operation of law, arising in the ordinary course of business, and for amounts which are not overdue for a period of more than 30 days or that are being contested in good faith by appropriate proceedings; and (c) Liens created pursuant to the Security Agreement.