Obalon Therapeutics (NSDQ:OBLN) said this week that it’s planning a share flotation worth $35 million that could swell by another $5 million if an over-allotment option is fulfilled.

The San Diego-based medical device company won pre-market approval from the FDA for its ingestible, gas-filled weight-loss balloon in September 2016. The Obalon device is indicated for weight loss in adults 30 to 100 pounds overweight, with a body mass index of 30 to 40, who have failed to lose weight through diet and exercise. The device is designed to be swallowed in a capsule. Once the capsule reaches the stomach, it inflates with gas, partially filling the stomach to help patients feel full and eat less. Up to three balloons may be added during treatment, after which they’re removed via an endoscopic procedure no longer than six months later.

The device hit the U.S. market in early 2017.

Obalon said Jan. 16 that it the forthcoming offering will consist of $35 million worth of common stock plus a $5.25 million underwriters over-allotment.

UBS Investment Bank, Canaccord Genuity and Stifel are the flotation’ss joint book-runners, with BTIG acting as a co-manager.