45NRTH Large Concave Carbide Aluminum Tire Studs - 300 Pack45NRTH utilizes a two piece construction method to create a reliable and high performing bicycle tire stud with a concave carbide aluminum design. The open space and edges created by the large concave crown result in twice the surface area for increased traction and grip. Sold in a pack of 300 We design 45NRTH tires for extreme winter cycling applications. We do not recommend this product be used with power assist bikes as the additional torque and