A packer consists of an aluminum cylinder fitted with an inflatable rubber sleeve. CUES packers are designed to have the smallest outside diameter (maximum clearance of pipe imperfections and obstructions) while still allowing the packer, when inflated, to seat firmly at the defective joint. They are also designed for maximum bypass flow while operating in the line. The design of the packer(s) allows the operator to remove the mixing stem for clean up without disassembling the packer.CUES provides a variety of joint testing and sealing packers which allow chemical sealant or root kill solutions to be injected into a defective joint. CUES packers include a simple design and are a cost-effective solution as compared to other methods.