Finis Axis Swimming Buoy Finis Axis Swimming Buoy DUAL-FUNCTION PULL BUOY The dual-function design of the Axis Buoy improves body position while building upper body strength and engaging the core muscles. With ergonomic keyholes and a contoured design, the Axis Buoy can function as both an ankle float and a leg buoy. The lightweight EVA foam is lightly textured for a more secure grip and allows swimmers to easily transfer the buoy between ankles and legs.