A useful and rather underrated item in Nethack 3.3.0 and 3.3.1. Zapping or engraving with a wand of enlightenment will show you all your intrinsics, just like a potion of enlightenment. This is great for identifying noncursed rings and amulets. Put on the amulet, zap the wand of enlightenment, and if "Your life will be saved" appears in the list of intrinsics, you know that it is an amulet of life saving. You can also use a wand of enlightenment to determine whether you can safely pray.