Yup, Dynamo1 and csifreakaholic got it. ;)
Gosh, Dynamo, I had no idea your name was David..that's cool! :)
#1 When I am filled
I can point the way,
When I am empty
Nothing moves me,
I have two skins
One without and one within.
#2 It's always 1 to 6,
it's always 15 to 20,
it's always 5...