November 28, 2016 at 8:56 pm
#5023269952
Alex Hodschayan
Keymaster
If they are black, they are -47 density. Sometimes the blue can darken. If there is any blue coloring, it is a -40. Who did you purchase from on Amazon? From Amazon or a third party seller on Amazon? If there are any questions about it, please give us a call. Sorry for the delayed response because of the Thanksgiving Holiday.