Provided is an apparatus that conveys container pre-forms comprising a first circulating carrier and a plurality of engagement devices constructed and arranged on the first circulating carrier. The blade includes a metallic base comprising an airfoil, a section of the airfoil comprising a recess within a surface of the airfoil, and a composite inlay disposed within and bonded to the recess. In another implementation, the signal derivative is filtered with a low-pass filter, and the cut-off frequency of the filter is adjusted in proportion to the measured variability of the signal. One or more spacers are provided that are selectively positioned between the inner piece and a shoulder in the front end of the body and a shoulder in the outer retaining piece, thus permitting adjustable axial positioning of the gating needle with respect to the central opening of the outer retaining piece.