The Parties shall perform the services agreed under this contract with the same care and diligence they apply to their own affairs and guarantee to base them on the known state of science and technology. No further guarantee is offered. Liability of the parties, legal representatives and agents in performance for any breach of essential contractual obligation (i.e. obligations the fulfilment of which allow the proper performance of the contract and on which the other party usually relies and may reasonably rely) shall be limited to intent and gross negligence, whereby liability for simple negligence shall be limited to foreseeable damage typical for this type of contract. Otherwise, the parties, their legal representatives and agents in performance shall be mutually liable only for intent and gross negligence. However, no such limitation of liability shall apply in the event of injury to life, body or health and where the product liability act applies. Notwithstanding Section 426 German Civil Code (BGB), the Parties agree that, in case of claims by third parties, in their internal relationship they shall only be liable in proportion to their share of fault and undertake to indemnify each other against further claims.