Volume attenuator for 100 V loudspeakers lines and maximum regulated power of 40 W. It includes paging security function by line commutation and speech preference. Volume regulation in 6 steps through 12 positions endless switch with “zero” inserted every two levels. Plate is 45 mm wide and compatible with all M-420x series Optimus frames (optional). Flush-mounting box included. OPTIMUS model ref. CV-40WE (white), CV-40IE (ivory), CV-40SE (silver) or CV-40BE (black).