An acousto-optic deflector (AOD) spatially controls the optical beam. Changes include a large plastic brass deflector mounted toward the rear of the ejection port. A wind deflector in place of the windscreen makes a helmet more or less mandatory. This height adjustment is relative to a deflector, which directs the inlet stream. These were equipped with life support systems, deflector shields, and FTL-drives. Initially, they protected the bodies with steel deflector plates, sandbags and mine conveyor belting. A windblocker or wind deflector minimizes noise and rushing air reaching the occupants. With others, the snowplow forms part of the obstacle deflector below the bufferbeam. The flame deflector on the Sea Launch platform broke off and sunk into the water. A T-shaped deflector was used for production M48 tanks. A wind deflector and neck warmers were available as options. Some two-stroke engines use pistons with a deflector head. Finally, in the 1950s, it acquired the Peppercorn-type of deflector plates. The XM4 was also given the cartridge deflector, as well as other minor refinements. Using a smoke deflector was never a tradition of Pennsylvania Railroad.