Washington, D.C. 20549


Proxy Statement Pursuant to Section 14(a) of the
Securities Exchange Act of 1934
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Definitive Proxy Statement
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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 December 18, 2018.











  Meeting Information  
  Meeting Type:          Annual Meeting  
  For holders as of:    October 25, 2018  
  Date: December 18, 2018          Time: 1:00 p.m., Pacific Time  
  Location: Meeting live via the Internet-please visit  
  The company will be hosting the meeting live via the Internet this year. To attend the meeting via the Internet please visit www.virtualshareholdermeeting.com/ZS2018 and be sure to have the information that is printed in the box marked by the arrow  (located on the following page).  


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:  
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 December 4, 2018 to facilitate timely delivery.  

—  How To Vote  —

Please Choose One of the Following Voting Methods


Vote By Internet:

Before The Meeting:

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.


During The Meeting:

Go to www.virtualshareholdermeeting.com/ZS2018. 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  
The Board of Directors recommends you vote FOR the following:


1. To elect two Class I directors to hold office until the 2021 annual meeting of stockholders or until their successors are elected and qualified, subject to their earlier death, resignation or removal.  
  01) Karen Blasing   
  02) Charles Giancarlo   
The Board of Directors recommends you vote FOR the following proposal:
2. To ratify the selection of PricewaterhouseCoopers LLP as our independent registered public accounting firm for fiscal year 2019.
NOTE: Such other business as may properly come before the meeting or any adjournment thereof.