These smartwatches are compatible w/ Wear OS 3 - 9to5Google

Google has so far confirmed that only a handful of current and upcoming smartwatches will be upgradeable to Wear OS 3 later this year.

Wear OS - Wikipedia

Wearos: Google Maps on WearOS affecting some smartwatch users: Here's how - Times of India

These smartwatches are compatible w/ Wear OS 3 - 9to5Google

Google Wear OS Will Solve its Second Biggest Problem with Version 4.0!

Wear OS 3.0 updates explained!

Fossil working with Google to bring Wear OS 3 support to its companion app

Wear OS smartwatches will get a major software update every year - SamMobile

Wear OS 3: Features, eligible smartwatches, and more

WhatsApp beta is now available for Google Wear OS smartwatches - Neowin

WhatsApp arrives on Wear OS this summer

Wear OS 3 Users Who Are Left-Handed Can Now Rotate the Screen 180 Degrees for Easy Operation

Wear OS is getting a revamped Play Store and offline Google Maps later this year : r/WearOS

New and Improved Features of Wear OS 4 in Galaxy Watch 6