A special device suitable for making PR knots and serving. Manufactured with stainless steel, ergonomic and compact, equipped with quick adjusting disc-drag that allows a perfect running. Tube with very strong hardened steel bush to prevent fraying. Equipped with two bobbins of different weight that permit the ideal tensioning of the tying. Each bobbin has lock line rubber rings that, in case of falling of the Rotoknotter, avoid damages to the boat. Supplied with complete instructions.