Sonnax O/D drum (bare drum, doesn't include clutches or steels)

This Sonnax Smart-Tech® Billet Overdrive Housing increases clutch apply surface area for better holding power in high-load applications and can be configured with either six dual-sided clutches or an HP clutch stack for maximum torque capacity.

• The description claims that the housing increases clutch apply surface area for better holding power in high-load applications.