Multi-split devices ensure the air-conditioning of several rooms. The optional combinations of internal devices and external units enable an optimum match to requirements. Subject to the external unit, between two and four internal devices can be connected. The internal devices offer many individual air-conditioning options. They are available as wall mounted version or as cassette for ceiling installation. The different versions of the internal devices offer many options for air-conditioning the most diverse rooms. The internal devices are available as wall mounted version as well as cassette units for integration into ceilings. The devices are further differentiated in accordance with their range of functions. Up to four internal devices can be combined with a single external unit. The cassette air-conditioning devices ACK i are designed for installation into ceilings. These devices are ideal solution for offices and commerce - whether you need to heat or cool.