PURPOSE: To easily eliminate remaining unbalance by counterposing a second ear on the circumference in addition to an ear of a normal single Oetiker formed at the superposed part, and forming one or more openings at the superposed part of inner and outer belt parts.

CONSTITUTION: A second ear part 23 is provided at the opposite position on the circumference against an ear part 13 of the inner belt portion 11a of a clamp belt 11 and further, an opening similar to an opening 36' is formed in the middle of the outer belt portion 11a and a second opening similar to an opening 46 is formed in the inner belt portion 11b when required. And an opening is preferably formed as well at the hook side opposite to the free end of the inner belt portion 11b. A small gap or a discontinuous part is provided within the zone of the second ear part 23 and the deformation of the second ear part 23 is minimized. The ropes 24, 25 of the second ear part and the clamp belt 11, 11 are brought close to each other and further, the clamp belt is made of a relatively thin material to minimize a generated step.