HHIP MWLNR 12-4B Turning Tool Holder - New Rigid Clamp Design Right hand. Zero degree relief. New rigid style top & hole clamping design provides increased stability & security for productive turning of large components and heavy machining. Use with WNMA, WNMG, WNMM inserts. Please see chart picture for sizing information. When replacing the insert, apply enough pressure to push the clamp forward and align it with the hole as you tighten it. Please see the video of the installation process.