Replacement Bonds In the event that any Bond is not delivered due to any occurrence, act or event beyond the control of the Depositor and of the Trustee (such a Bond being herein called a "Special Bond"), the Depositor may so certify to the Trustee and instruct the Trustee to purchase Replacement Bonds which have been selected by the Depositor having a cost and an aggregate principal amount not in excess of the cost and aggregate principal amount of the Special Bonds not so delivered. To be eligible for inclusion in the Trust, the Replacement Bonds which the Depositor selects must: (i) for Trusts containing municipal bonds, yield current interest which is exempt from taxation for federal income tax purposes and, if the Trust is a State Trust, exempt from taxation under the personal income tax law of the particular state involved; (ii) have a fixed maturity or disposition date comparable to the bonds replaced; (iii) be purchased at a price that results in a yield to maturity and in a current return, in each case as of the execution and delivery of the applicable Reference Trust Agreement, which is approximately equivalent to the yield maturity and current return of the Special Bonds which failed to be delivered and for which the Replacement Bonds are substituted; (iv) be purchased within twenty days after delivery of notice of the failed contract to the Trustee or to the Depositor, whichever occurs first and (v) be of comparable credit quality to the Special Bond which failed to be delivered. Any Replacement Bonds received by the Trustee shall be deposited hereunder and shall be subject to the terms and conditions of this Indenture to the same extent as other Bonds deposited hereunder. No such deposit of Replacement Bonds shall be made after the earlier of (i) 90 days after the date of execution and delivery of the applicable Reference Trust Agreement or (ii) the first Distribution Date to occur after the date of execution and delivery of the applicable Reference Trust Agreement.