Harken’s integral hydraulic backstay adjuster provides the power to optimize sail shape quickly.  the cylinder features a built-in, double-acting pump that delivers oil when the handle is both pushed and pulled.  This moves oil through the system twice as fast as single-acting pumps on other integrals.

Assemblies include a hardcoat-anodized aluminum cylinder and pump, vale, gauge, and stainless pump handle. The handle can be used in three different ways: either on its own (the handle is inserted to pump, then immediately removed), with an O-ring that secures the handle in the socket but still allows for removal, or with a pin to permanently mount the handle. All pins and plugs are stainless steel.  Cylinders include a clevis pin on both ends.  Standard eye-jaw toggles fit all harken cylinders.

The pressure-release knob turns clockwise to close and pump, counterclockwise to release.  when closing the pump, the knob cannot be over-tightened by hand, preventing damage to the valve.  Release speed depends on how far open the know is turned  Pressure relief is factory set to prevent crew from over-tensioning the backstay.

Harken integral backstay adjusters come in four sizes to fit boats with 5-10 mm (7/32 – 3/8″) wire – approximately 9 – 18 m (30-60′)

***Harken recommends attaching a toggle to the cylinder’s bottom clevis pin to accommodate stay movement.  Standard eye-jaw toggles fit all Harken cylinders.