Abstract: A sheath, including a sheath body, a handle, and a traction wire. The traction wire includes a first traction wire. The handle includes a first guide rail member and a first slider. The first slider is connected to the first traction wire. A first groove is provided on an outer wall of the first guide rail member along an axial direction. The first groove includes a first bottom and a first side wall. The first slider slides in the first groove along the first side wall so as to drive the first traction wire to move. At least part of the outer wall of the first guide rail member is radially recessed to a central shaft of the first guide rail member to form the first groove.