The Shadow's own pen contained a colorless fluid, that had dried almost instantly.

The new pens contained only little whirlwinds of dust.

His pen contained a fluid that vanished after drying.

Such pens will usually not contain straw or other material.

The pens still contained several feet of water, filled with strange luminescent fish and plants.

Each "pen" contained a modern desk and a small table set at a right angle to the desk.

The special pen contained a small radio transmitter which told the special pad where it was writing.

A wireless digital pen contains an infrared camera that reads the dot pattern to determine the exact location on the board.

These special pens, which often look something like a highlighter, contain iodine that changes color when it comes in contact with cellulose.

Parents love Magna Doodle because the pen contains neither ink nor paint to spill.