Ring 4 Size Smart Ring vs Water Resistant Watch Model 8R500 - Men: which is safer?

Oura Ring 4 Size Smart Ring is our pick: better on PFAS and on the overall hazard picture.

Our pick

Oura Ring 4 Size Smart Ring

Oura

Ring 4 Size Smart Ring

PFAS grade

Excellent 85/100

Overall grade

Excellent 81/100

Verdict

Buy

Hazard flags

⚑ 1

Material

Titanium case

Confidence

35%

PossibleBacterial growth and biofilm on skin contact surfaces

TomTom Water Resistant Watch Model 8R500 - Men

TomTom

Water Resistant Watch Model 8R500 - Men

PFAS grade

Excellent 85/100

Overall grade

Excellent 77/100

Verdict

Buy

Hazard flags

⚑ 2

Material

On watch case and band

Confidence

35%

PossiblePolymer case and band degradation

PossibleBacterial or mold growth in seals and band

Where these two actually differ

  • We flag Bacterial growth and biofilm on skin contact surfaces on the Oura and not on the TomTom.
  • We flag Polymer case and band degradation and Bacterial or mold growth in seals and band on the TomTom and not on the Oura.
  • The Oura is Titanium case where the TomTom is On watch case and 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.

Both products run through the same public rubric: materials, coatings, brand disclosure, lab findings, and recalls, plus a beyond-PFAS hazard analysis. Grades are model-based estimates, not lab tests. How grades work →

More waterproof fitness trackers & cases: see the full ranking