A side looper comprises an entry guide for directing a longitudinally moving long product into an arcuate path, an exit guide for receiving the product exiting from the arcuate path, and inner and outer guide walls arranged between the entry and exit guides. The guide walls are adjustable between mutually spaced closed positions fixing the curvature of the arcuate path, and open positions allowing the curvature of the arcuate path to either increase or decrease.