PURPOSE: To increase a degree of freedom in a grip position so as to improve operability by providing a mounting bolt for fixing inner/outer holders by a screw.

CONSTITUTION: An inner holder 1, having a handle pipe use hole 5 with a handle pipe 13 insertable in the center, having a screw hole 6 coming into contact with a surface of the handle pipe 13 from on a circumference of the inner holder 1 and having an external shape capable of fitting an outer holder 2, is provided. The outer holder 2, having a mounting bolt use screw hole 8 on a line of the same position to the screw hole 6 of this inner holder 1, is provided. To the screw hole 6 of the inner holder 1, a handle pipe 5 is fixed by a screw 3, and the outer holder 2 is made to coincide with the inner holder 1, to screw by a mounting bolt 4 to the screw hole 6 and to the mounting bolt use screw hole 8. In this way, a degree of freedom of a grip position is increased to enable operability to improve.