A device for connecting a longitudinal bar to a pedicle screw for fixation of the spine includes a body having an axis, an upper end, a lower end, a hole coaxial with the axis, and a through hole positioned perpendicular to the axis. The device also includes a collet chuck slidably disposed within the hole. The collet chuck includes a through hole substantially aligned with the through hole of the body for receiving the longitudinal bar. The collet chuck also includes a chamber defined by elastic tongues for receiving the head of the pedicle screw.