Suitable for bikes with 4 cm or smaller diameter tube For Gopro Hero 1 / Hero 2 / Hero 3 / Hero 3+ camerasProduct: bicycle handlebar seatpost mount for Gopro Hero camera + 3 Way Pivot Arm Model: ST-02 Material: plastic, metal Color: black Clamp size: about 12 x 7.8 x 2.0 cm 3 way pivot arm size: 5 x 3.3 x 1.6 cm Suitable for tubes with diameter no more than 4 cm Compatible with Gopro Hero 3+/3/2/1