These pullers have an outer sleeve that provides a complete seal around the ducting, preventing any fluids or contaminants from entering either the duct or the pulling eye. The pulling head is manufactured from alloy steel and is designed to protect the mechanism from heavy knocks or side loads. It is also fully sealed to prevent any fluid entry. Care should be taken at all times not to exceed the yield value of the ducting since this may cause permanent deformation to the duct as well as loss to the integrity of the polyethylene These duct pullers are installed quickly and easily and require no special tooling. A new tooth profile makes removal much easier than the earlier models Duct wall thickness is normally designated by an SDR value. The lower the SDR value, the heavier the wall thickness. These products can be used on SDR 9 through SDR 17 ducting and Schedule 40 pipe.