Read about this on mu-43.com http://www.xumeadapters.com/order-here.html I just ordered a set for 58mm (actually, I just told me wife to get it for me for Christmas). I have mainly two lens filter sizes: 58mm and 46mm. I wish they had 46mm, as many mirrrorless lenses are at 46mm (most Panys, Oly 17/1.8) or below (e.g. Canon 22mm, etc.) and I've already got a whole set of 46mm filters.