system: You are a contract-analysis assistant performing a span-extraction task. You are given an excerpt from a commercial contract and the name of a clause type to locate within it.

Return the exact text of the requested clause, copied verbatim from the excerpt — identical wording and punctuation, with no paraphrasing, summarising, explanation, or added commentary.

The excerpt is one window of a much longer contract and often will not contain the requested clause. If the requested clause does not appear in this excerpt, respond with exactly: Not found.

Output only the extracted clause text, or the exact string `Not found.` — nothing else.

user: Contract excerpt:
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the SENDER shall be comprised by these General Clauses and by the Specific Conditions subscribed by the Parties. All current legal provisions shall apply thereto and therefore the Parties are obliged to fulfill them regardless of whether or not they are stated in this document or in the Specific Conditions. PARTIES: The Parties of the Contract shall be: ECOPETROL S A, hereinafter ECOPETROL, a company of mixed economy, authorized by law 1118 of 2006, attached to the Ministry of Mines and Energy, acting pursuant to its by-laws with its main domicile in Bogotá D C with Tax ID 899.999.068- 1, represented by whoever subscribes the Specific Conditions of the Contract and the SENDER, identified as indicated in the Specific Conditions, who is obliged subject to the conditions and terms set forth herein. ECOPETROL and the SENDER may also be called in this Shipment Contract or "Contract", individually as the "Party" or jointly as the "Parties". RECITALS: By virtue of the above the parties agree: CLAUSE FIRST PURPOSE 1. ECOPETROL is the owner of the pipelines of private use indicated in the Specific Conditions (hereinafter, the "Pipelines"). 2. Currently the Pipelines have Available Capacity for the shipment of crudes from third parties. 3. The SENDER has crude oils of its own/production that wishes to ship through the Pipelines under the conditions established in this Contract and its annexes, with the quality specifications set forth by ECOPETROL for its shipment through the Pipelines. 4. The Parties have agreed to enter into this Contract under the "Spot" shipping contract modality, by virtue of which, the SENDER shall be obliged to pay the shipping fee applicable for the barrels effectively shipped through the Pipelines during the Month of Operation and subject to the existence of Available Capacity. 5. The SENDER knows and accepts in all its terms the Manual of the Shipper of the Pipelines, which is an integral part of the Contract hereof as Annex 1. 1.1 ECOPETROL is obliged within the terms and conditions set out in this Contract, its annexes and in the applicable regulations, to ship through the Pipeline, from the Entrance Points agreed and detailed in the Specific Conditions to the Exit Points agreed and detailed in Specific Conditions, crudes owned/produced by the SENDER and delivered in the Entrance Points pursuant to the instructions and procedures set out by ECOPETROL (hereinafter, the "Service"). 1 CLAUSE SECOND DEFINITIONS 2.1 All capitalized terms shall have the meaning as defined in the Clauses of this Contract and/or in Clause 2 of the Manual of the Shipper of ECOPETROL. CLAUSE THIRD TERM 3.1 The Contract shall be in force during the period indicated in the Specific Conditions. 3.2 The term of execution of the Service for the Contracted Capacity being the purpose of the Contract hereof may be extended by common agreement between the Parties by a document subscribed prior to the date of termination of the Contract, subject to the existence of Available Capacity in the Pipeline during the month of Operation in which the Service is to be provided. 3.3 the obligation of the monthly payment borne by the SENDER for the Service shall be made during the totality of the term of execution of the Contract. CLAUSE FOURTH AMOUNT OF THE CONTRACT 4.1 The initial estimated amount of the Contract hereof is as indicated in the Specific Conditions. The final amount of the Contract shall correspond to the total of the actual invoicing by ECOPETROL and shall be established upon termination and final liquidation of the same. 1.2 By virtue of this Contract and as indicated in the Specific Conditions, the SENDER shall have a limited capacity for shipment by the Pipeline of crudes of its own/production, subject to the existence of Available Capacity during the month of operation of the Service (hereinafter, the "Contracted Capacity"). 1.3 The scope of the obligations of ECOPETROL is limited to the reception, custody, shipment, decanting, and indispensable storage for the transportation and shipment of Crude to the SENDER. 1.4 The Contract hereof does not include the provision of the unloading service in unloading areas, the treatment of crudes, the storage in export terminals, or any terminal services. It is the responsibility of the SENDER to execute or contract these services whenever it may be necessary. The SENDER shall wave and hold ECOPETROL harmless for any damage or prejudice suffered by ECOPETROL as a result of failing to receive the Crude in the Exit Point, either by lack of the services before mentioned or
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Extract the exact clause related to "Warranty Duration" from the excerpt above.