The 'BU' filter bottles are designed in order to accommodate a piece of binchotan charcoal being placed inside in order to help purify the water. The 'BU' bottle itself is crafted using minimalistic materials including glass-like plastic and a bamboo top.
The design of the 'BU' bottle follows traditional Japanese design methods in order to create a piece of equipment that is sturdy, strong yet inherently sustainable. The incorporation of bamboo into the filter bottles via the top portion help to make it more of a sustainable design. The use of binchotan helps to eliminate the need for manufactured filters, which makes the 'BU' bottle a more sustainable solution when it comes to purifying water.