A refrigerant bypassing and filtering apparatus of an air conditioner is disclosed which is capable of effectively removing foreign matter such as slag produced in a refrigerant line, not only when the air conditioner is initially operated, but also during normal operation of the air conditioner. The novel compounds are used as therapeutics for treating andor preventing various medical dysfunctions and diseases arising from reactive oxygen species andor excess Zn ions, in particular stroke, Parkinson’s disease, Alzheimer’s disease. The modular primary structure may include a plurality of information handling systems arranged in racks within it. An anti-rotation member is associated with the dilator andor the sheath, which prevents the dilator from rotating relative to the sheath as the rotatable fastener is rotated, and also included are means which allow a user to overcome the anti-rotation features without damage to or inadvertent separation the sheath.