Helio Smart Ring Health Tracker vs Silicone Sport Watch Band Black Unisex Strap Rock blue / 20mm: which is safer?

Where these two actually differ

• We flag Polymer band composition and residual monomers and Bacterial growth in sealed band-case junction on the Amazfit and not on the Polar.
• We flag Bacterial and mold growth (maintenance-dependent), Polymer degradation and microplastic generation and Allergic contact dermatitis on the Polar and not on the Amazfit.
• The Amazfit is Titanium alloy case, polymer band where the Polar is silicone elastomer strap, which is most of the difference in these two grades.
• These two are level, close enough that price and fit should decide it rather than our grade.
• We are less certain about the Amazfit grade, at 35% confidence against 72%, because it discloses less.