Provides a smooth adjustable tension to your web while unwinding (paying off the roll). Torque can be varied using a controller. For constant torque without feedback use WT-PDC-05 controller. For constant tension with feedback use VA-816 and Load Cell. May also be controlled with a PLC (programmable logic controller) Voltage is constant at 24 volts DC. Vary the current to vary the torque. See table for maximum current. Port for air cooling.