It is very densely packed with lights. On the fullness of the needles - even after fluffing, it has some holes where you can see through but not super noticeable and works for us. The light bulbs come out of the attached strings and it *seems* like one ought to be able to plug in lighted ornaments instead, however, when I try this, several of the other lights go out and ornament does not light up. It's possible I'm not pushing hard enough to get the ornament's plug into the tree's light socket, but I didn't want to risk breaking anything. So we just put the lighted ornaments on a separate string of lights we've used for this purpose in the past.