The Swedish firm Teenage Engineering, mostly known for the award winning OP-1 synthesizer, has introduced a sustainable version of its OP-11 wireless speaker. The outer cube shell of the big speaker is made entirely with holocellulose, a  completely recyclable material derived from normal wood by removing lignin through a newly-researched method. The pure white color of the speaker, which isn’t obtained through bleaching or painting, is a trademark characteristic of the material. The experimental nature of the holocellulose version of the OP-11 is especially fitting, considering that the OP-11 was already a remake of the iconic loudspeaker created by Swedish sound-design genius Stig Carlsson in 1974.