June 27, 1996 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 Re: Infrasonics, Inc. -- Removal from Registration Ladies and Gentlemen: Effective June 27, 1996 Infrasonics, Inc. (the"Company") has been merged with and into Nellcor Puritan Bennett, Inc. ("NPB"). Accordingly, the Company requests that the unsold securities registered under the following registration statements be removed from registration pursuant to an undertaking under Section 512(a) of Regulation S-K: 1. An aggregate of 25,000 shares of the Company's Common Stock issuable upon the exercise of options granted under the Company's 1983 Employee Stock Option Plan and registered under Registration Statements on Form S-8 (Nos. 33-01250m and 33-10515); 2. 22,000 shares of the Company's Common Stock issuable upon the exercise of options granted to certain directors and registered under a Registration Statement on Form S-8 (No. 33-44698) 3. An aggregate of 362,139 shares of the Company's Common Stock issuable upon the exercise of options granted or to be granted under the Company's 1991 Stock Option Plan and registered on a Registration Statements on Form S-8 (Nos. 33-45244 and 33-45245); 4. 37,500 shares of the Company's Common Stock issuable upon the exercise of a warrant granted to a consultant to the Company and registered on a Registration Statement on Form S-2 (No. 33-88402); and 5. 515,900 shares of the Company's Common Stock issuable upon exercise of options granted or to be granted under the Company's 1995 Stock Option Plan and registered on a Registration Statement on Form S-8 (No. 33-64037). The Company understands that, under Rule 477(b) under the Securities Act of 1933, as amended, this requested removal is effective upon the filing of this letter. Very truly yours, /s/ Frederick C McGee _____________________ Frederick C. McGee Vice President of Finance and Chief Financial Officer