Often, straps for bundled items require relatively flexible adjustment mechanisms to facilitate the installation of the strap tensioner and to adjust the length of the strap. Colleagues also need locking mechanism with relatively stable locking function to lock the belt tensioner to a constant length, and the existing common eccentric buckle achieved, but the traditional eccentric buckle body and handle are not easily separated. Engage each other, eccentric buckle body and handle in adjusting the length of the belt fixed separately, the operation is very inconvenient, the traditional eccentricity when the buckle is connected to the belt, the belt adjustment is not convenient tightening is not easy.