... inner tube extension in order to compensate for the difference in overall reaming shell length. Combined high quality and design make our reaming shells ... covered no matter what your requirements are. Size Available: "Q" Series: AQ, BQ, NQ, HQ, PQ (Front end & Back end Type ... , EWT, AWT, BWT, NWT, HWT (Single Tube/Double Tube) WG Series: EWG, AWG, BWG, NWG, HWG (Single Tube/Double Tube) WM ...