UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No.     )

  Filed by the Registrant    ☒                                                              Filed by a party other than the Registrant    ☐

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☐	Preliminary Proxy Statement
☐	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
☐	Definitive Proxy Statement
☒	Definitive Additional Materials
☐	Soliciting Material Pursuant to §240.14a-12

IDEX Corporation (Name of Registrant as Specified In Its Charter)
(Name of Person(s) Filing Proxy Statement, if Other Than The Registrant)
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☐	Check box if any part of the fee is offset as provided by Exchange Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee was paid previously. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.
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	*** Exercise Your Right to Vote *** Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to Be Held on April 25, 2018.
	IDEX CORPORATION		Meeting Information
			Meeting Type:      Annual Meeting
			For holders as of: March 2, 2018
			Date:  April 25, 2018	Time: 9:00 a.m., Central Time
			Location:   Lincolnshire Marriott Resort
	IDEX CORPORATION         1925 W. FIELD CT, SUITE 200         LAKE FOREST, IL 60045		Ten Marriott Drive               Lincolnshire, Illinois 60069
		You are receiving this communication because you hold shares in the company named above. This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side). We encourage you to access and review all of the important information contained in the proxy materials before voting.
			See the reverse side of this notice to obtain proxy materials and voting instructions.

— Before You Vote —

How to Access the Proxy Materials

	Proxy Materials Available to VIEW or RECEIVE:
	PROXY STATEMENT             2017 ANNUAL REPORT
	How to View Online:
	Have the information that is printed in the box marked by the arrow (located on the following page) and visit: www.proxyvote.com.
	How to Request and Receive a PAPER or E-MAIL Copy:
	If you want to receive a paper or e-mail copy of these documents, you must request one. There is NO charge for requesting a copy. Please choose one of the following methods to make your request:
	1) BY INTERNET:	www.proxyvote.com
	2) BY TELEPHONE:	1-800-579-1639
	3) BY E-MAIL*:	sendmaterial@proxyvote.com
	*  If requesting materials by e-mail, please send a blank e-mail with the information that is printed in the box marked by the arrow (located on the following page) in the subject line.
	Requests, instructions and other inquiries sent to this e-mail address will NOT be forwarded to your investment advisor. Please make the request as instructed above on or before April 11, 2018 to facilitate timely delivery.
	— How To Vote — Please Choose One of the Following Voting Methods
	Vote In Person: Many stockholder meetings have attendance requirements including, but not limited to, the possession of an attendance ticket issued by the entity holding the meeting. Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares.
	Vote By Internet: To vote now by Internet, go to www.proxyvote.com. Have the information that is printed in the box marked by the arrow (located on the following page) available and follow the instructions. Vote By Mail: You can vote by mail by requesting a paper copy of the materials, which will include a proxy card.

		Voting Items
	THIS PROXY, WHEN PROPERLY EXECUTED, WILL BE VOTED IN THE MANNER DIRECTED HEREIN BY THE UNDERSIGNED STOCKHOLDER. IF NO DIRECTION IS MADE, THIS PROXY WILL BE VOTED FOR PROPOSALS 1, 2 AND 3. IF ANY OTHER MATTERS PROPERLY COME BEFORE THE MEETING, THE PERSONS NAMED IN THIS PROXY WILL VOTE IN THEIR DISCRETION. 1.  To elect three directors each for a term of three years     Nominees:     01)     WILLIAM M. COOK     02)     CYNTHIA J. WARNER     03)     MARK A. BUTHMAN
	2.  Advisory vote to approve named executive officer compensation. 3.  Ratification of the appointment of Deloitte & Touche LLP as our independent registered accounting firm for 2018.