An apparatus comprising a tubular housing having an axial length L and a circumferential length C. A first canopy secured to the tubular housing around a perimeter of the first canopy, the first canopy extends for an axial length L1 that is less than L and for a circumferential length C1 that is less than C/2. The first canopy has a front sloping section and a rear sloping section that extend from the perimeter to a semicircular outer perimeter. A second canopy disposed circumferentially opposite the first canopy and secured to the tubular housing around a perimeter of the second canopy. The second canopy extends an axial length L2 that is less than L and a circumferential length C2 that is less than C/2. The second canopy has a front sloping section and a rear sloping section that extend from the perimeter to a semicircular outer perimeter.