This round hole suction strainer is used on the suction end of a suction hose to help prevent debris from being sucked into your pump. It is a critical component as it can help prevent your suction pump from being damaged or clogged. This strainer is made of zinc plated, cold rolled steel for extra durability. It has a female NPT thread and will connect to a the male NPT nipple on your suction hose. Gloxco Suction strainers are meant to be attached to the submersed end of a suction hose and is used to keep debris from entering your suction hose and pump.