This double ribbed ovolo style is an alternative to the rounding over cutter. If the cutter is lowered a top quirk can be produced.

Specification:
D=28.7 mm
C=1/2 inch
C=12.7 mm
B=9.5 mm
B2=12.7 mm
R=4 mm
R2=4 mm
OL=64 mm
Shank Diameter=1/4 inch