SWING ARM NUT SOCKET WRENCH It is used to undo and tighten the 38mm diameter swing arm nut with four 7mm grooves. A 1/2" square hole to fit a standard ratchet or torque wrench. Inner Dia.∮33.95+0.1mm / Outer Dia.∮43-0.1mm It fits the following Kawasaki models: ZX 6R (600) 2005-2010, ZX 6RR 2005, ZX 6R (636) 2005-2006, ZX 10R 2004-2010, Z 1000 2010, GTR 1400 2008-2010, ZZR 1400 2006-2010 and others.