Elastic band is fixed to be detained

The utility model discloses an elastic band is fixed to be detained, a serial communication port, include: detain the seat, with detain the knot cap that the seat is connected detain the seat with it buckles the core to be provided with in the knot cap, wherein, detain the seat with be provided with a barb groove and no. Two barb grooves on the knot cap respectively, detain the core and be three hole toper structures, and both sides are provided with the overhead kick tooth. The utility model discloses in impel and combine an organic whole become through detaining the seat and detaining barb groove on the cap, can only follow a direction and carry out the erection joint to the free activity that prevents to detain the seat and detain the cap and separating detains the core simultaneously and is three hole toper structures, the overhead kick tooth of elastic band through detaining the core both sides with buckles the seat and carries out the interlock, make the elastic band more and more tighter, have easy to