Minnesota medical device maker Cardiovascular Systems plans to offer more than 2.1 million shares of its common stock, a potential take of $70 million based on the company’s estimates.

Cardiovascular Systems announced this week an upcoming stock offering worth up to $70 million in net proceeds, according to an early estimate.

The device maker has yet to issue share pricing or the date of the sale, but said in prospectus documents that net proceeds are expected to be about $60.8 million or as much as $70 million if underwriters exercise in full their option to purchase additional shares.