1、Aluminum Alloy Material: The narrow wide chainring are forged from lightweight all aluminum alloy, surface anodized, high precision positive and negative gear positioning, strong impact resistance, and obvious anti rust effect. 2、Good Performance: The positive and negative tooth positioning groove has strong biting force, arc cutting angle, positive and negative wide and narrow tooth shape design, reducing chain wear, chain and gear piece are closely attached, not easy to drop the chain, and efficient transmission. 3、Mud Discharge Oblique Mouth: Mountain bike 38T narrow wide chainring uses oblique openings for mud discharge to prevent sediment accumulation and smooth transmission. 4、Scope of Application: Bicycle narrow wide chainring uses standard 4 plate hole BCD104mm installation specification, high compatibility, suitable for a variety of 4 jaw mountain cranks. 5、Commodity Size: Outer diameter is 160mm/6.3in, adjacent hole center distance is 74mm/2.9in, distance between center holes BCD is 104mm/4.1in, inner diameter is 88mm/3.5in, installation inner hole diameter is 10mm/0.4in, thickness is 4mm/0.16in Item Type: Mountain Bike Narrow Wide Chainring Material: Aluminum Alloy Weight: Approx. 95g/3.4oz Commodity Size: Outer Diameter: Approx. 160mm/6.3in Adjacent Hole Center Distance: Approx. 74mm/2.9in Distance Between Center Holes BCD: Approx. 104mm/4.1in Inner Diameter: Approx. 88mm/3.5in Installation Inner Hole Diameter: Approx. 10mm/0.4in Thickness: Approx. 4mm/0.16in Number of Teeth: 38T 1 x Narrow Wide Chainring