Model: CX square hole crank. Crank weight: about 510g. Material: aluminum alloy. Material: AL 7075-T651 Alloy, aerospace grade. Model: Snail round BCD 104 chain ring, 4-arm. Fit for: Most Shiman.o. Weight: 30T 38g,32T 38g,34T 48g,36T 52g 38T 70g,40T 75g,42T 92g.