Polaris Industries Inc. acquired 509 Inc., maker of carbon fiber snowmobile helmets and other products, adding to its portfolio of accessory brands.

509, which started in Spokane, Wash., in 2004, joins brands like Klim, Kolpin and Pro-Armor that Polaris has acquired in recent years. Terms of the transaction, announced late Monday, were not disclosed.

"We are always exploring opportunities to make Polaris a stronger, more competitive global company," Steve Eastman, president of Polaris' parts, garments and accessories unit, said in a statement. "As we look toward the future, parts, garments and accessories will continue to be a growth driver for Polaris."

Tom Delanoy, founder of 509, will continue as president of the business.

Polaris grew familiar with the 509 brand over the last three years by working on a co-branded line of snowmobile goggles. "We like their products, we like their brand and we like their team," Eastman said.

Medina-based Polaris, a maker of all-terrain vehicles, motorcycles and snowmobiles, had 2014 annual sales of $4.5 billion. The parts, garments and accessories business, the company's second-largest segment, accounted for $742 million, or 17 percent, of that.

Eastman is a former Target executive who joined Polaris in February 2012 and has nearly doubled the size of what Polaris calls its PG&A business.

During Eastman's tenure, Polaris acquired Klim, a maker of technical riding gear for snowmobile and motorcycle riders, in December 2012. It added Kolpin Outdoors, which makes hunting, shooting and other accessories for ATV and off-road vehicles, in April 2014 and Pro-Armor, maker of ATV accessories, in November 2014.

Polaris shares, which were trading for as much as $158.24 last February, closed at $87.22 Tuesday, off $1.14 for the day.