Used amidships, and also at the stern of craft with a transom. You may need a bit of keelband to protect the deck edge.
Very neat, but be sure that the fasteners are far enough inboard to be strong.
Used at the bow, and the stern of double enders. You can have a half pair, but please let us know which one you need.
Not sure I'm entirely convinced by lipped fairleads, since the fasteners are inevitably close to the edge of the rail, and so may not be very strong. If that is a problem, you may be better off to fit the fairleads inboard, and then a strip of keelband to protect the deck edge
More secure than the handed lipped fairleads
The good news is that stray lines will never catch in these. The bad news is that all lines have to be fed through them. The nominal size is the size of the opening.
If the rail is not deep enough for bulwark fairleads, these could be an answer. They are also less likely to catch stray sheets than conventional fairleads, and so are suitable for placing amidships for springs.
The good news is that stray lines will never catch in these. The bad news is that all lines have to be fed through them.