The Compact Catapult Pack (weight 25 lbs) unpacks and is deployed normally as a working catapult. When packed back using the Empty Pack, it transforms into a Portable Catapult (weight 250 lbs).

well its just like when we go on vacation and unpack your suitcases....you can't seem to fit all that stuff back in like we did the first time around!

*please note sarcasm*