Abstract: A housing adapted for receiving a sonic transducer capable of projecting and receiving a sonic pattern having a primary lobe and a secondary lobe. The housing has an end wall for receiving the sonic transducer and a restrictive wall for intercepting the secondary lobe of the sonic pattern in one quadrant and reflecting that portion of the secondary lobe into the opposite quadrant. A pair of side walls substantially intercept and reflect the secondary lobe in quadrants adjacent the one quardant to provide more uniform sonic pattern. The side walls may be disposed at an angle outward from the direction of projection of the primary lobe having a value of from 0.2 to 0.3 of the value of the angle the secondary lobe makes with the primary lobe.