SureClose 108 and 57 models are concealed hydraulic gate closers. The models feature Final Snap-Close Action (FSA) which increases speed at the end of closing to overcome electric or coded locks. Both ‘Closing Speed’ and ‘Final Snap’ are adjustable using the supplied adjustment tool. Designed to never leak hydraulic fluid, the SureClose 108 or 57 are extremely safe and do not offer resistance if closed quickly in an emergency. Soft, quiet closure also protects the latching/locking system. Safe for pool area installation. * NO hold-open feature.* When installing this hinge to a swimming pool gate always confirm any safety requirements with your local Council