Abstract: A connection unit includes a hollow first part, a hollow second part and two positioning wires. The first part includes a positioning hole defined radially therein and an insertion section extends from an end of the first part. A groove is defined radially in an outer surface of the insertion section. The second part is securely inserted in one end of a hollow tube and the two positioning wires are located in the second part and two ends of each of the positioning wires are engaged with two insertion holes defined in the second part. The second part is mounted to the insertion section of the first part, and the two positioning wires are engaged with the groove so that the first part is rotatable. Two ends of a connector are inserted into two respective first parts respectively and positioned by two pins.