Fsa dh alloy cnc chainring 3mmfsa 4 bolt precision cnc machined al7075t6 alloy 3mm thick chainrings with recessed chainring bolts from either side fsa dh alloy cnc chainring featuressizes 104mm x 34 36 38 40 42 t4 bolt 104mm bcd3mm thick black anodized with laser logos single chainring use for 8 or 9 speed systemsbuy fsa components from chain reaction cycles the worlds largest online bike store