Not an OAKLEY product.This product was developed by ourselves.Please Don't heat!!The TR 90 material itself is strong against heat. But glue to prevent lens scratch can melt and prescription clip can be deformed. Because the TR 90 material is flexible, your optician can put the lens in the clip.Prescription clip to the inside of your sunglasses. Bring it to your eye doctor, have them place your prescription in it.1. SUTRO is used in sport sunglasses.2. Korea production (design, production) MADE IN KOREA3. unbroken TR 90 material (material only Sunglasses)4. Very light weight5. Mounting is very easy.6. Easy to carry.7. Prescription clips prevent internal sunglasses lens scratches8. Suitable for sports sunglasses that wear glasses.