Our Premium 1X 104 & 64bcd Oval traction chainrings are designed for any cranks that use 104bcd mounting interface. This is the most common mounting standard for Shimano and other 4 arm cranks.Size (Weight):?64BCD: 26T (35g), 28T (42g)30T 104BCD: 36g - comes with special bolts and spacers104BCD: 32T (41g), 34T (44g), 36T (53g)Compatibility:?All cranks with 4x 104BCD interface. That means Shimano XT / Zee / Deore / SLX / XTR, Race Face, FSA, E13 and many more. 9, 10, 11 and 12spd Eagle compatible.?Material:?cnc machined 7075 Txxx Aluminum. Long-lasting constructionChainline:26 & 28T (64bcd) - 46mm30T - 48mm32T - 48.5mm34 & 36T - 50mmMounting holes:?4 x 104mm BCD (for 32T ring, bolts should be min 6mm long)Ovality: Optimized to each size separately. Range: 10.2-14.4% and Timing of 110.5-116.3? after TDC (top dead center) Patent PendingAdvantages of our special Oval chainrings:Finest design to provide excellent weight to strength ratioOne of a kind special oval shape (Patent Pending)Unique Patent Pending narrow-wide teeth profiles to keep your chain in place for minimum 12 months!Special 3D teeth machining for ultimate mud relief decrease wear and noise dramaticallyDesigned to handle mud and grass with easySuperb quality and great look.You will ride faster using ovals. If you keep using round ring then others will get quicker.Reduces stress on knees and helps to maintain your legs fresher for longer.You will not feel the oval shape at all.