A reducer comprises a reducing shaft for engaging a stabilization member, a reducer body for engaging a pedicle screw extender and receiving the reducing shaft along an axis, and one or more of a three-pawl clutch mechanism, a three-stage locking mechanism and a closure mechanism. The clutch mechanism comprises a clutch housing comprising a central passage into which the reducing shaft extends and ports intersecting the central passage, a clutch knob surrounding the clutch housing, and clutch pawls disposed within the ports. The locking mechanism attaches the reducer body to the pedicle screw extender and comprises a first pivoting lever comprising a toothed end, a second pivoting lever comprising a socket for engaging the tooth, and a protrusion configured to engage the pedicle screw extender. The closure mechanism comprises a driver shaft extending through the reducing shaft and a biasing element to bias the driver shaft to a retracted position.