NOTE: Post mounting brackets sold separately. The recommended setup requires two hinges and two mounting brackets. SureClose Double Acting Hinges for weld-on applications. Allows a gate to swing 90 degrees in either direction. Made for center mount applications. Requires minimum post size of 2-1/2" x 2-1/2" Self-closing or non-self closing versions available. Self-closing version closes from 0 to 85 degrees and holds open from 86-90 degrees. Hold open feature renders this hinge not suitable for child/pool safety. See swing diagram above for a clear visual representation of this info. Hydraulics are concealed within the post, providing a controlled and quiet close in a tamper resistant design that will not leak. Adjustable self-closing speed. Does not offer resistance if closed quickly in an emergency. Features dual thrust ball bearings to help withstand heavy loads. Hinge gap between frame and gate is adjustable, from 2-1/2" - 3". Pre-threaded post mounting brackets allow for horizontal adjustment. These hinges can be used in any of the following combinations: Use 2 of our SKU 928544 to self-close a gate up to 180 pounds*. Use 1 of our SKU 928544 and 1 of SKU 928542 to self-close a gate up to 90 pounds*. Use 2 of our SKU 928542 to hold a gate up to 1500 pounds* (will not self-close). * Weight ratings based on a maximum gate size of 72" high x 40" wide.