Most bulbs will only give off UVB rays at distances of 6-12". This one reaches 20". Anu is very active and really seems to be doing well with these lights.
You;re right and I'm so glad they finally came out with the 10, my turtles, when they are not sunning themselves, are futher away than the 12" the 5.0 can reach. It's so important they get their UVB.