13D Filing: Discovery Group I, LLC and Entellus Medical Inc (ENTL)

Item 3 of the Schedule 13D is hereby amended
to read in its entirety as follows:

The total purchase price for the 2,100,232
shares of Common Stock beneficially owned by the Reporting Persons as of May 5, 2017 was approximately $31,189,886. The source
of such funds was the assets of Discovery Equity Partners, including proceeds of margin loans under margin loan facilities maintained
in the ordinary course of business by Discovery Equity Partners with a broker on customary terms and conditions. Discovery Equity
Partners is the legal owner of all of the Common Stock beneficially owned by Discovery Group.

Item 5 of the Schedule 13D is hereby amended
to read in its entirety as follows:

The information concerning percentages of ownership
set forth below is based on 21,916,451 shares of Common Stock outstanding as of April
27, 2017 in the Company’s Quarterly Report on Form 10-Q for the quarter ended March
31, 2017.

Discovery Equity Partners beneficially owns
2,100,232 shares of Common Stock as of May 5, 2017, which represents 9.6% of the outstanding
Common Stock.

Discovery Group beneficially owns 2,100,232
shares of Common Stock as of May 5, 2017, which represents 9.6% of the outstanding
Common Stock.

Discovery
Group is the investment manager of Discovery Equity Partners.   Discovery Group exercises ultimate voting and dispositive
power of the securities held by Discovery Equity Partners. As a consequence, Discovery Group may be deemed to share beneficial
ownership of all of the shares of Common Stock owned by Discovery Equity Partners. Voting and disposition decisions at Discovery
Group with respect to the investment of such securities are made by a five-person investment committee (the “Committee”)
which makes such investment decisions by majority vote. No member of the Committee may act individually to vote or sell shares
of Common Stock held by Discovery Equity Partners, nor does any such member have a veto right concerning the vote or sale of any
such common stock. Accordingly, no individual member of the Committee is deemed to beneficially own, and each individual member
of the Committee expressly disclaims beneficial ownership of, within the meaning of Rule 13d-3, any shares of Common Stock held
by Discovery Equity Partners solely by virtue of the fact that he or she is a member of the Committee.

The transactions in Common Stock effected by
the Reporting Persons since those reported in the Schedule 13D filed by the Reporting Persons on March 28, 2017 are set out in
Exhibit 1 hereto.

No person other than Discovery
Equity Partners is known to any Reporting Person to have the right to receive or the power to direct the receipt of dividends
from, or the proceeds from the sale of, any of the shares of Common Stock reported herein.

Item 6 of the Schedule 13D is hereby amended
to read in its entirety as follows:

There
are no contracts, arrangements, understandings or relationships (legal or otherwise) between or among any of the Reporting Persons
and any other person with respect to any securities of the Company other than the governing documents of Discovery Group and Discovery
Equity Partners, the margin loan facilities referred to under Item 3 above, the Joint Filing Agreement of the Reporting Persons
with respect to the Schedule 13D that was included as an exhibit thereto, the Joint Filing Agreement of the Reporting Persons with
respect to this Amendment No. 3 included as Exhibit 2 to this Amendment No. 3, and the Power of Attorney granted by
Michael R. Murphy with respect to reports under Section 13 of the Securities Exchange Act of 1934, as amended, which Power of Attorney
is included as Exhibit 3 to this Amendment No. 3.

List of transactions effected by the
Reporting Persons in the Company’s Common Stock since those reported in the Schedule 13D filed by the Reporting Persons
on March 28, 2017.

Joint Filing Agreement dated as of May
8, 2017, by and between Discovery Equity Partners and Discovery Group.