This is the L-42mm - 1Dot Front Spring Set from XRay.
FRONT linear springs have been specifically designed to complement the big-bore shocks. Spring rate is constant during the entire spring compression. Marked with 1 DOT for easy identification. These springs extend the existing springs line up for further set-up adjustments.
The springs, like all the other XRAY springs, are manually measured, selected and matched into pairs to guarantee precisely equal length and damping characteristics.