Self-guiding cutters for rounding over edges do not require a side fence.
They are supplied with two bearings.
Use the larger bearing for a round-over.
If the cutter is lowered a top quirk can be produced.
Bullnose mouldings can also be produced by taking a second pass from the opposite side of the workpiece.

Specification:
D1=2 1/2 inches
D1=63.5 mm
C=1 1/4 inches
C=32 mm
B=9.5 mm
R1=1 inches
R1=25.4 mm
OL=88.5 mm
Shank Diameter=1/2