Adventure watch maker Garmin took a subtle dig at Apple over its new Watch Ultra: 'We measure battery life in months. Not hours."

• Garmin tweeted last week that it measures battery life in months, "not hours."
• The apparent jab came after Apple unveiled its first watch geared toward extreme athletes.

Apple waded into the adventure watch market last week, and Garmin, a leading player in the space, took notice.

At Apple's annual fall event, the company rolled out a number of new products, including the Watch Ultra. It's a brand-new product geared toward extreme athletes, like scuba divers and hikers, and represents the first time Apple has branched out of its core general fitness offerings.

Garmin, on the other hand, was founded in 1989 and has long been known for such GPS-oriented trackers and watches for activities like watersports, cycling, and running.

The company tweeted a day after Apple's event highlighting its Enduro 2 watch, which rolled out in August.

"We measure battery life in months. Not hours," Garmin tweeted, an apparent reference to Apple emphasizing the Watch Ultra's 36-hour battery life. Apple did not immediately respond to Insider's request for comment on the ad.

Garmin does list battery life in hours as well as days for its products — the Enduro 2, for example, can last up to 46 days in smartwatch mode, 550 days using solar in battery saver mode, and 110 hours in GPS mode.

Apple said its new watch has 36 hours of battery life and has the biggest battery of any Apple watch yet, although a new power saver mode will roll out this fall that will raise that to 60 hours.

The Ultra comes with a bright display that makes it easier for the wearer to read in harsh sunlight and speakers to hear even in windy conditions, Apple said last week. There's a compass on its face, improved GPS capabilities, and can be customized for mountain, trail, and ocean activities.

It starts at $799.