High-impedance (primary) volume controller with autotransformer, 20 W/100 V, 3-wire mandatory listening, white/black/silver knob, without frame. The AT 20T volume control features a control circuit with a 6-position (5 + off) selector and a separate transformer. - Designed for use in 100 V line systems to adjust the volume of a loudspeaker group with a total power not exceeding 20 W. - All connected loudspeakers must have 100 V line matching transformers. - Can be configured (via internal jumper) to work with 3-wire lines for emergency announcements at maximum volume. - Installation on any standard European electrical wall plate is possible by drilling a hole and securing the control circuit. - Includes 3 knobs in white, silver, and anthracite colors. - The transformer can be placed inside a wall or flush-mounted box where the control circuit is located. Features: - Attenuator for constant voltage systems, max 20W. - Universal mounting on any standard European electrical wall plate. General specifications: - Input voltage: 100 V - Output voltage: 100 – 70 – 50 – 35 – 25 – 0 V - Maximum power: 20 W - Attenuation: 0 dB – 3 dB – 6 dB – 9 dB – 12 dB – OFF - Max Depth: 50 / 1.96 mm/inch Physical specifications: - Height: 53 / 2.08 mm/inch - Width: 35 / 1.37 mm/inch - Depth: 68 / 2.67 mm/inch - Net Weight: 0.16 / 0.35 Kg/Lbs Shipping information: - Package height: 120 / 4.72 mm/inch - Package width: 70 / 2.75 mm/inch - Package depth: 75 / 2.95 mm/inch