About Product:Size: switch posted bore 8.5 cm thickness about 1 cm applies (8.3-8.7 cm of single opened-switch) switch posted od 18.5*16.5 cm border wide 5 cm (manual measurement save slightly errors) special tips: behind is with duplex rubber to fixed Yu wall surface of, if some special wall surface material stick not prison, can themselves buy some duplex rubber fixed because stick not prison off down of, not is quality problem Oh,