Driveshaft Shop is proud to announce their line of spools. These spools, in both 27 spline (metric 1.098 o.d.) and our extreme series 28 spline (domestic 1.225 o.d.) The new 28 spline spools are 50% stronger and can only be used with our extreme level 6 systems or for use with our new custom ordering system. Spools available in both 4130 chromoly and 7075 aluminum.