I wanted metal as a material when it falls down times then just only a small dent in it and not even the whole box broken! I opted for this model, and I am absolutely satisfied. It fits into a pack of pads, can be locked hermetically and the coffee aroma was listed even after my last three-week vacation in the pads.
Conclusion: Anyone who wants to keep his coffee very sensible, without these "evaporate" has the best choice with these products hit!