Polar M400 vs Polar RS300X GPS: What is the difference?
User manual Polar RS300X (English - 62 pages)
Amazon.com : HQRP Battery (4-Pack) Compatible with Polar RS300X Heart Rate Monitor (2 Batteries Compatible with Training Computer + 2 Batteries Compatible with Transmitter Polar WearLink) : Sports & Outdoors
LaughingPlace.com on X: "Scanning into #Disneyland for the first time with my #MagicBandPlus was a breeze. I have to admit I've wanted this for a while. No more fishing for my phone