Models HFB and VFB are backstopping clutching designed to prevent reverse rotation of shafts in applications that have large shaft diameters of up to 6.0 inches and low backstopping torque requirements. HFB & VFB backstops have Sprag clutch technology with high inner race overrunning speed, are ball bearing supported and protected with integral lip seals. The clutch housing is prevented from rotating with a torque arm and is mounted on a stub shaft with a locking ring for easy mounting. Clutches are selected by shaft size and torque requirement.