CZ Smart Interchangeable Leather Smartwatch Strap vs Helio Smart Ring Health Tracker: which is safer?

Where these two actually differ

• We flag Chromium (hexavalent) from leather tanning, Formaldehyde resins in leather finishing, Azo dyes in leather coloring and Bacterial or fungal growth on worn leather on the Citizen and not on the Amazfit.
• We flag Polymer band composition and residual monomers and Bacterial growth in sealed band-case junction on the Amazfit and not on the Citizen.
• The Citizen is Leather, stainless steel hardware where the Amazfit is Titanium alloy case, polymer band, 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.