Greetings, All: Will beg forgiveness in advance for my ignorance. What innocently began a few months ago as a quest to replace a pair of Juliets my wife lost on a Christmad roadtrip has now resulted in us completely falling down the X-metal rabbit hole. We have now bought 5 Juliets, 1 R2, and 1 Half-X. Along the way, we've learned there are different sized rubbers (15, 25, 50, 75...) to help accommodate various head and face shapes and sizes, but we have no real idea how to translate those numbers in the best way for us. I'm a big guy with a wide skull, and my wife is petite with a small round face. One of the Juliets and the R2 and the Half-X are for me to wear, and the remaining 4 Juliets are for my wife. Armed with that little bit of info, can anybody tell us which size rubbers might give us the best fit for comfort and grip for each of those different sunglasses? We aren't collecting or flipping, just came late to the party and now need some guidance that helps us NOT disassemble and reassemble everything 3 or 4 times just to try on different rubbers. Any and all advice is much appreciated.