Joseph Guerra and Sina Sohrab are Visibility, a New York-based design studio specialising in the creation of simple, functional products. None of their designs rely on the use of expensive materials or fitting into a collective design aesthetic. Rather, each answers its own unique problem, exploring the limitations of products that currently exist on the market and improving them through small but important modifications to their function. Among other things they’ve created a beautiful briefcase fashioned from laser-cut polypropylene – which transforms it from luxury item into universal object – and they’ve revolutionised the humble broom, adding a pivoting head to give it increased usability and minimise damage in storage. Seriously clever stuff.