Machined from a thick plate of aluminum, the Spiders have a Heat Treated CrMo Steel insert pressed into them to mate with the splines on your Profile BB Spindle.
Four Arm (104BCD/mm) and 5 arm (110BCD/mm) versions are available now.
The Sinz 4 bolt chainrings do not fit our spiders. Profile, Sharp, Rennen, and Shimano 104bcd 4 arm chainrings all fit perfectly.
CHAINRING BOLTS NOT SOLD BY PROFILE