This high quality in-wall volume control is easy to install and you can conveniently locate it anywhere for locally controlling remote-sited speakers. Suitable for all standard 2-gang electrical boxes that are 47mm deep. (The use of MK or other good quality metal boxes is recomended. Rubber grommets must be used in the 'knock-out' holes to prevent speaker cable chafing. * Transformer design for maximum efficiency * 60 Watts RMS per channel * Accepts speaker cable up to 2.5mm in diameter * Suitable for speakers rated at 4, 6 or 8 ohms * Frequency response 20-20,000Hz