The new CAT-3L Loop Unwinder / Rewinder uses two user-positioned photo-detectors to start and stop the unwinding or rewinding action. The CAT-3L was developed primarily for unwinding applications. When the upper photo-detector is uncovered by the paper loop, unwinding begins and continues until the lower photo-detector is covered, when it stops. This approach reduces the paper resistance to the printer to almost zero and offers a far greater reliability than tension-arm systems. The CAT-3L can also be used to rewind, however the rewound roll will be very loose as there is almost no tension on the roll. All models use two visible-light photo-detectors with cables that plug in to the rear panel of the machine. The cables are 79” (2-meters) long. The detection range is adjustable from 3/4” to 15-3/4” (20-to 400-mm.)