Siro II: Multifunctional Seat Shell Underframe for All Demands Siro II combines quality and functionality with a sophisticated frame concept and a stylish design. Siro II not only features a seat unit completely tiltable by 35° and a completely stowable back as standard components, but also a wide range of additive equipment. Thus your individual therapy and adjustment options are next to unlimited. Siro II guarantees highest mobility and decisively increases the quality of life of its users and their attendants.