Collar shaft anodes are fitted
when there is insufficient space
for the streamlined shape.
Select smaller sizes for shafts
from 3/4" to1 1/2" and up to 35mm
Larger sizes from 1 3/4" to 5"
and also metric to 50mm.

Where the outside diameter allows collars can
be bored out to intermediate sizes. The width
can be machined down. . . . Zincsmart Home