Masimo Announces Closing of IPO and Exercise of Underwriters' Over-Allotment Option

August 13, 2007

Over-allotment option brings total offering amount to over $232 million

IRVINE, Calif., Aug. 13 /PRNewswire-FirstCall/ -- Masimo Corporation (Nasdaq: MASI), the inventor of Pulse CO-Oximetry and Read-Through Motion and Low Perfusion pulse oximetry, today announced that it has closed its previously announced initial public offering of 11,916,626 shares and that the underwriters of the offering have exercised their over-allotment option and purchased 1,787,494 additional shares of common stock at the public offering price of $17 per share. Including the over-allotment, the Company and selling stockholders sold 13,704,120 shares in the offering for gross proceeds of $232,970,040. Excluding shares offered by selling shareholders, net proceeds to the company amounted to approximately $48 million after deducting the underwriting discounts and commission and the estimated offering expenses.

Piper Jaffray & Co., Deutsche Bank Securities Inc. and Citigroup Global Markets Inc. acted as joint book running managers for the offering. Cowen and Company, LLC and Thomas Weisel Partners LLC, acted as co-managers of the offering. A copy of the final prospectus relating to the offering can be obtained from the Piper Jaffray & Co. Prospectus Department, phone (612) 303-6000.

The registration statement relating to the initial public offering of common shares has been declared effective by the Securities and Exchange Commission. This press release does not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of such common shares in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

About Masimo

Masimo develops innovative monitoring technologies that significantly improve patient care-helping solve "unsolvable" problems. In 1995, the company debuted Read-Through Motion and Low Perfusion pulse oximetry, known as SET and with it substantially reduced false alarms and increased pulse oximetry's ability to detect life-threatening events. More than 100 independent clinical and laboratory studies have confirmed that Masimo SET technology allows clinicians to accurately monitor blood oxygen saturation in critical care situations. Our Masimo SET platform has significantly addressed many of the previous technology limitations, has substantially contributed to improved patient outcomes and has been referred to by several industry sources as the gold standard in pulse oximetry. In 2005, Masimo introduced Masimo Rainbow SET Pulse CO-Oximetry, which, for the first time, noninvasively monitors the level of carbon monoxide and methemoglobin in the blood, allowing early detection and treatment of potentially life-threatening conditions. Founded in 1989, Masimo has the mission of "Improving Patient Outcomes and Reducing Cost of Care by Taking Noninvasive Monitoring to New Sites and Applications." Additional information about Masimo and its products may be found at

Forward-Looking Statements

This press release includes forward-looking statements. All statements other than statements of historical facts included in this press release that address activities, events or developments that we expect, believe or anticipate will or may occur in the future are forward-looking statements including, in particular, the statements about our plans, objectives, strategies and prospects regarding, among other things, the financial condition, results of operations and business of ours and our subsidiaries. These forward-looking statements are based on current expectations about future events affecting us and are subject to uncertainties and factors relating to our operations and business environment, all of which are difficult to predict and many of which are beyond our control. Certain factors mentioned in this press release, including the risks outlined under "Risk Factors" in our Prospectus dated August 7, 2007, will be important in determining future results. Although we believe that the expectations reflected in our forward-looking statements are reasonable, we do not know whether our expectations will prove correct. They can be affected by inaccurate assumptions we might make or by known or unknown risks and uncertainties. All forward-looking statements included in this press release are expressly qualified in their entirety by the foregoing cautionary statements. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. We do not undertake any obligation to update, amend or clarify these forward-looking statements or the risk factors contained in our Prospectus dated August 7, 2007, whether as a result of new information, future events or otherwise, except as may be required under the federal securities laws.

SOURCE Masimo Corporation
CONTACT: investors, Mark de Raad, Executive Vice President and Chief Financial Officer, +1-949-297-7041,] or media Tom McCall, V.P. Marketing Communications, +1-949-297-7075,, both of Masimo Corporation or Nick Laudico of The Ruth Group, +1-646-536-7030,, for Masimo Corporation

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