A written agreement where an agent guarantees the supply of a maximum amount of natural gas during a determined period, without interruptions, when the condition of probable shortage arises and up to five (5) additional calendar days defined at the buyer’s discretion. Buyer shall pay a premium for the right to take up to the maximum quantity of gas, and a supply price upon delivery of the nominated gas. The nominated quantities must be accepted by the seller upon exercise of the option. The premium shall be paid monthly. (R. CREG 186-220; Art. 1)