A synchrotilt chair includes a base, a back, a seat, and a link pivoted to a rear of the base and to a bottom of the back to form a four-bar linkage arrangement. A back panel module may have a back panel and a side panel. 35 dBkm, and preferably less than about 0. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline material layer. The body includes a plurality of engaging members formed thereon, and the illumination device includes a casing having an engaging groove for releasably engaging with one of the engaging members of the body.