i have the C Mask glasses im a spectacle wearer so have the insert as well, started out with Pilla then changed to these when purple lenses were all the rage and for the price of a single Pilla lens I got a 3 lens set plus the frames and a carry case. The fit is very similar to Pillas and I didn't find any difference sight wise between the 2 and the price of new lenses direct from Castellani is way cheaper than Pilla. The lenses appear to be interchangeable but they don't quite fit (hence the reason for buying more lenses) and I easily sold the Pillas which paid for everything
