The Heliroller housing has an ID Bore of 2", a width of 4". At one end of the housing there is a .25" thick x 2.25"OD spacer.

The heliroller is 4" wide x 5.5" tall. The 6 rollers mount around the outside of the housing at 45 degree angles off center. The housing is 4" wide x 5" tall; the rollers make it 5.5".

The 6 rollers mounted around the housing are 3.35" wide, 1.75"OD at the center, and 1.3"OD at the ends. They can be removed with a wrench.