The most important thing about a new construction recessed lighting fixture is that it must be installed from above the ceiling.
As you can see from the picture, there is a frame that is nailed to the ceiling joists and which in turn hold both the can and the junction box, where the wire splices are made.
This style of can is good when a house is being first built, and when the attic is easily accessible (not full of ducts and insulation).
If you are adding recessed lighting as a remodeling project, there is a style of recessed lighting can make for remodels.
And speaking of recessed lighting for your home ….. we would love to install some for you when you live in or near Woodside.