I have done this puck in the past and it has gotten some good reactions. Just as the description
says, the frame, which usually can be given out for inspection, is shown to be solid plastic all the
way. A card is slipped in and a pen or pencil is pushed all the way through leaving the plastic
unharmed.
Just be careful who you hand it to. I've had someone almost break it trying to
push a pen through it afterwards. Other than that, this is a great trick. Especially for kids.