The Profile Design Sonic Ergo 52a Aerobar is a reliable aluminum extension that combines the Sonic bracket’s an extensive fit range low weight and easy adjustment and minimal frontal area with the Ergo armrest to create an aerobar that will aid most riders in optimizing their position for both speed and comfort. The 52a extensions have a 52deg for the grip. The rider can choose whether to hold high for the shrugged position or low for a more open head up position.