Precise Fit Every Time for Oura Ring 4This professional ring sizing kit is perfectly compatible with Oura Ring 4, allowing you to measure your finger accurately before placing an order. Get the ideal fit that ensures long-lasting comfort for daily wear, whether for yourself or as a thoughtful gift for loved ones. Super Easy to Use with Reliable AccuracySimply follow the numbered markings on the sizing card to complete your finger measurement. For smoother testing and a more accurate fit that mimics real wearing comfort, you can apply a small amount of olive oil to help the sizer slide on effortlessly. Versatile Fit for Any Finger & Extended Testing SuggestionThis smart ring sizing kit works seamlessly for any finger on either hand — index, middle, or ring finger are all ideal choices. For the most reliable sizing result, we recommend wearing the sizer for at least 24 hours to account for natural finger size fluctuations throughout the day. Smart Shopping Solution to Avoid Unnecessary HassleUse our accurate ring sizer to confirm your perfect size in advance. This simple step helps you skip the trouble of returns or exchanges, saving you time and effort on post-purchase adjustments. Tailored Sizing for Oura Ring 4 (Sizes 4–15 Whole Sizes Only)Oura Ring 4 sizing differs slightly from regular standard ring sizes, making this dedicated sizing kit a must-have for finding your best fit. The kit covers whole sizes from 4 to 15 — note that half sizes are not included in this set.