Profile Design T2 DL Aluminum Aerobar. The Profile Design T2 DL aluminum aerobar is optimized to achieve the perfect aero position on a road bike used in the occasional triathlon. The shorter length of the extensions puts you right into the aero position without over extending. Plus, these aerobars are ITU Draft Legal hence the DL in the name when used with the included bridge. The extension itself is construction of aluminum and can be adjusted in length from 120mm to 170mm. Furthermore, there's an additional world of adjustability to fine tune one's aero position courtesy of the J2 brackets and F 19a aluminum armrests. And for maximum versatility, the aerobar's clamp is compatible with both 31.8mm and 26.0mm bars.