This small altar intended for private devotion shows the Virgin and Christ child in the centre, flanked by St Catherine on the right and St Mary Magdalene on the left. The right wing shows St Peter and the left wing shows St Paul. Objects such as this were intended to be portable, and sometimes had travel cases. The Embriachi were a family of entrepreneurs and carvers from north Italy. They appear to have operated workshops in Florence and Venice, where they employed local workers specialising in certosina (inlay of stained woods, bone and horn). The workshop produced items in carved bone with certosina ornament.