I will always use fuse. I have purchased 3 pairs of polarized sunglass replacement lenses and they have all exceeded any pair of lens on all sunglasses I have ever owned including Armani and Maui Jim. The lenses I have bought were for pairs of Electrics and a pair of Von Zippers. They fit in the frame perfectly. I can only wear polarized shades or I will get headaches really bad which tells me these are 100% legit. I strongly suggest you buy yourself a pair on sunglasses you have even the smallest scratch. Speaking of scratches, these lens are incredibly scratch resistant and I have yet put the smallest mark even after dropping them on the cement twice. You can see through these perfectly and I'm sure you yourself would notice the difference immediately. I DID NOT receive and discounts for my review. This is 100% legit and from the heart. Buy these and you'll never want another stock pair of lenses ever again!Worked well