Have used this for myself for years, so purchased for Dad. Online web site helped sizing, especially since this was a gift. More expensive than some clip on, but good investment. Treat with care and will last.These are great overming glasses and work really well for driving. But keep them always in the case because they break very easilyI wear these for golf and they are great.Good product value, while it lasts ! Clips easily broken off, so I’m on my 3rd pair now but don’t mind based on low price !Got these when my old clip-on sunglasses broke. The optics of these are SO much better then my old ones. There is NO lens distortion at all and it does the polarization stuff. They are a bit flimsy in that the lenses are thin plastic that are not in a frame but just held together by the nose piece. But this is probably why the optics are so good - my old pair had thicker lenses bound by a frame and caused visual distortion - I didn't realize how much until I used these. So even if these break more often than another pair might, it's worth it for the optics.This is supposed to be the same size (54 RecG) as the previous dark shade clip-on shades (not previously ordered from this seller) we've used for his thicker plastic frames. These, however, while they fit, seem to be a little less wide and the clips are tighter on the frame. I'm not sure they will hold up to constant putting on and taking off. Only time will tell on that.My new glasses are large. These were the largest clip-ons that I could find but I could not get these Dioptics Solar Shield G REC Clip On Sunglasses Polarized Rectangular, Black, 58 mm to fit over my frames. These clip-ons have plastic clips that are attached directly to the lenses so I could not adjust them at all. The center spring is also plastic and attached to the lenses. I have some older Solar Shield clip-ons that have a metal frame and spring. They are smaller but I was able to adjust the metal clips because they are attached to the metal frame.It seems to me that Solar Shield either went out of business or were sold to another company. I miss the old Solar Shield web site and products.This product would probably work well with the correctly sized glasses. There are sizing charts available on the Foster Grant website.Great for reducing glare ; no complaints