Based on this product's specifications, here are some alternatives and similar models
Smart ring activity tracker Amazfit Helio Ring Titanium (size 12)
Summary description:
The Amazfit Helio Ring is a smart ring activity tracker made of titanium. It features a round form factor, weighs only 3.82 g, and has a thickness of 2.6 mm. With a battery life of up to 4 days and a capacity of 20.5 mAh, it charges in just 1.4 hours. Compatible with various Android versions, this sleek device is perfect for tracking your daily activities discreetly.