The 25-357A 20W/70V stereo audio line attenuator features flush mount auto transformer type. Fits into standard single gang box or ring. Excellent for use in home, paging and background music systems. Features a 10-position volume selector switch with 3dB step attenuation and a positive off position. Complete with stainless steel mounting plate, knob, with terminal block connectors. First 2 steps are 6dB and others are 3dB.