designer's own words:_Background ; According to the 3rd survey of Korea waste statistical (Korea national Institute of Environmental Research), the amount of using a PET bottle of a day per one person is 46.7g in the Republic of Korea. This occupies the second-largest amount after papers in all of recycle wastes. Thus, the amount of used PET bottle takes much space in the standard plastic garbage bag and recycling basket because it occupies large volume. So we replace that than the need be. And there is much expenditure in recycling process. If there is decrease in PET bottle volume, we can save time and resources for recycling process. Also, If all of PET bottle users decrease PET bottle volume, we can get a big synergy effect. _Concept ; This PET bottle motivated from an accordion. Users can compress this bottle in proportion as amount of water. So it is possible that we can decrease the unnecessary space. The strong point of this design is that it is much more convenient for putting in a bag portably and more compact for recycle. What we want from this design is that each person can considers and practices the protection of environment from simple and easy behaviors.