Wolf Tooth 76 BCD gears work great on any spider or crankset with 76 BCD. Drop-Stop® Technology - Patented Wolf Tooth gear geometry has a wide tooth side for maximum contact with the drive side, which distributes load and improves durability. The narrow side allows mud and dirt to pass through, reducing friction. Weight: 30t - 45g | 32 - 51g Material: 7075-T6 aluminum Made in USA