How the part fits? This male hinge connects to a gate post with a 3" outside diameter. 

Where is it installed? The male hinge clamps to the gate post. 

How many do you need? For most gates, 2 female hinges and 2 male hinges are required. For gates taller than 6 feet, additional hinges are recommended.

3" inside diameter, .83 lbs

The 3” male hinge clamps to a gate post with a 3" outside diameter. The pin of the male hinge connects to the female hinge (sold separately), while the female hinge clamps to the gate frame. This connection allows the gate to freely open and close.