I have never seen a fingernail mask before, and thought is may be something new to try out.
These were hard to work with, getting them all on to each finger while wearing them. They kept falling off as they were loose fitting. Because of the fit I didn't find they pushed against the nail enough to moisturise the nail without pushing them against my nails.
Before and After;
Not something I found was useful, they didn't stay on the nails and as soon as you moved your fingers they fell off. The suggestion said leave on for 30 to 60 minutes which was difficult. They did hydrate the finger tips and nails but I imagine that was down to the high quantities of glycerin. They would have worked better if the caps were elastic or something similar so it gripped to the fingertips.