At any time from time to time upon the reasonable request of Purchaser, at the sole expense of the applicable Seller, such Seller shall promptly and duly execute and deliver such further instruments and documents and take such further actions as Purchaser may deem necessary or desirable to (i) obtain or preserve the security interest granted hereunder, (ii) ensure that such security interest remains fully perfected at all times and remains at all times first in priority as against all other creditors of Seller (whether or not existing as of the Closing Date or in the future) and (iii) obtain or preserve the rights and powers herein granted (including, among other things, filing such UCC financing statements as Purchaser may request). If any amount payable under or in connection with any of the Collateral shall be or become evidenced by any promissory note, other instrument or certificated security, such note, instrument or certificated security shall be promptly delivered to Purchaser, duly endorsed in a manner satisfactory to Purchaser, to be itself held as Collateral pursuant to the Transaction Documents.