Squigly Squigly's Brain Teasers

Question:

What do you throw out when you want to use it, but take in when you don't want to use it?

Answer:

An anchor.

Try another Brain Teaser:

500 at the beginning, 500 at the end,
5 in the middle is seen,
The first of all letters, the first of all figures
Take up their stations between,
String them all together, and you will see
The name of an ancient king.