Reliable and sturdy: the wheel tyre snow studs are made of carbon steel, aluminum and hard alloy, which are sturdy and reliable, tough and firm, with nice strength and fine craftsmanship, not easy to break, rust or corrode, so as to you for a long time Size details: the snow tire spikes trims measure about 4 x 9mm , the compact size is very suitable for bicycle, boot, motorcycle and more; Please check the dimension details carefully before placing an order Practical function: the screw in tire studs can increase the friction between the tire and the ground, so as to improve the stability of the vehicle in the process of running, very suitable for driving or riding on days, and the small size is also applicable for snow boots, allowing you to go climbing, hiking, camping without sliding and falling easily Easy and quick to install: the hard alloy tire stud screws are very easy to install with the included installation tool, just simply put the screw on the drill machine with the metal