Abstract: A fluid flow control for controlling the speed of a piston in a fluid power cylinder is disclosed in which the flow control is located within the confines of the cylinder and includes a rotatable disk having tearshaped slots for communication of the exhaust fluid through the disk and out of the cylinder through discharge ports. Rotation of the disk to selectively position greater or lesser width portions of the tearshaped slot relative to an exhaust discharge opening in the cylinder permits selective, variable adjustment and throttling of the exhaust fluid to control the speed of movement of the piston in the cylinder.