A band 12 includes a center portion C, a pair of intermediate portions M, and a pair of outer end portions E. The center portion C is formed from a first band member 40 and that extends in a circumferential direction. Each intermediate portion M is formed from a second band member 42 and that extends so as to form a mesh-like shape. The second band member 42 includes a plurality of first tilt portions 44 extending so as to be tilted relative to the circumferential direction and a plurality of second tilt portions 46 extending so as to be tilted relative to the circumferential direction in a direction opposite to a direction in which the first tilt portions 44 are tilted. Each outer end portion E is formed from a third band member 54 and that extends in the circumferential direction.