i also have this layer on my avatar.
The other answers are wrong. i have tried other skins that i got in SL markets, a whole load of other skins, and the layer never disappears. The avatar is age verified weeks ago, settings revised to Adult, i have tried reset to the basic avatar and the layer is still there. the only solution seems to me to kill the avi and begin again.
I have no idea what it is and SL help becaomes increasingly impenetrable - its is impossible ven to find where to get advice, never mind an answer!