This Agreement constitutes the entire understanding and agreement between Plaintiffs, on the one hand, and Defendants, on the other hand, with respect to the subject matter of this Agreement and, as such, supersedes any prior understandings, agreements, representations, warranties, promises or covenants between Plaintiffs and Defendants, written or oral. The express terms of this Agreement control and supersede any course of performance or usage of the trade that may be inconsistent with any of the terms contained in this Agreement. This Agreement shall not be amended, modified, altered or otherwise changed, except in writing, signed by all Parties hereto, and expressly stating that it is an amendment of this Agreement.