Primary springs control engagement and shift rate. Made from high tensile wire and will hold rate better than cheap springs. The first force number listed controls what RPM your clutch engages and the second number controls how fast the clutch upshifts. Force Lbs. @ 2.50in. - 1.19in..

2009 fits POL 600 Dragon SP
2006 fits POL 600 HO Fusion
2003-2004 fits POL 600 PRO X
2000-2005 fits POL 600 XC SP
2007 fits POL 700 Dragon
2003-2004 fits POL 700 PRO X
2000-2005 fits POL 700 XC SP
2003 fits POL 800 PRO X
2001-2004 fits POL 800 XC SP
2006 fits POL 900 Fusion