This is a 3/4" Tank Adapter with a Brass SWIVELLING Snap-On Connector. The connector swivels through 360 degrees and reduces the chance of the hose kinking or snagging.
It can be used with any tank or drum with standard 1/2" (13 mm) garden hose pipe.
Firstly, you will need to drill a hole (25 / 27 mm diameter) where you want to locate the item.
Important.....You must be able to get your hand into the tank or drum somewhere close to enable tightening of the back nut. You will also need to make sure that the area where the hole is being drilled is reasonably flat.
You will not get a good watertight seal on a heavily curved surface (a slight contour will be OK).
Once you have drilled the hole, remove the back nut and rubber sealing washer from the adapter and push the threaded section through the hole.
Then push the rubber sealing washer back over the threaded section and finish by screwing home the back nut as tight as you can by hand. Do not overtighten.