Designed to provide easy and direct power to optimize your sail shape in a matter of seconds. Featuring a built-in double acting pump that delivers oil when the handle is both pulled and pushed allowing for a faster, more utilizable product. It's built with a hard-coat anodized aluminum cylinder and pump, valve, gauge, and handle, it allows sailors to attach it via three option: pin installs for a permanent handle, O-ring for a secure handle in the socket, or a non locking handle installs without O-ring and roll pin. For releasing the pressure turn the knob counterclockwise, and to build pressure turn the knob clockwise to close and pump. Designed to keep the pump valve from being damaged, the knob cannot be over-tightened. Built with an analog pump mounted at the top of the cylinder for reading pressure increments from 0 to 5000psi, you can carefully monitor the amount of pressure released which depends on how far and fast you turn the knob counterclockwise to open. If you have any questions regarding boat size in regards to which Integral Adjuster to install, please feel free to give us a call and we'll be happy to help.