The 20? Extension includes a solid cast iron tailstock support block for outboard turning. The support block raises the tailstock back to centerline for stability & additional material support when outboard turning. It is supplied with a Tool-Rest Extender. The 20? Extension can be mounted in 4 different positions including headstock or tailstock end of the bed as a bed extension, low on the leg for outboard turning, or perpendicular to the headstock for superior tool rest positioning.