The TengTools Rigger Jigger is an essential for every rower as they undo every nut in a European boat - 10mm for the riggers and 13mm for the top nuts. Angled, compact, special ring spanner with 12 point opening. The ideal compact ring spanner for the most popular fastening sizes (10/13mm). Total length 120mm. Ideal to keep in a pocket. DIN3113A