The Morphie Juice Pack is worth its weight in gold for charging my iPad and iPhone when travelling as it solves the dilemma of choosing which of your devices to charge when they are both running low on power and you have only 1 conventional power supply available to you. I have not yet worked out its charging capacity in real terms but it comfortably managed to charge both devices from virtually flat to full and still indicated 2 of the 4 capacity LED's.
The design is simple, practical and beautiful, I don't know what the material is but it feels tactile in your hand and is non slip. The charger fits into a jacket pocket easily and is not heavy.
I would highly recommend this to anyone who travels or uses multiple apple devices heavily without easy access to main supply