a coupling mechanism for interfacing between a wiper and a wiper arm comprises an connector and at least one width - adjusting spacer member . the connector has a body , and the two sides of the body are defined as the outer side walls . the body has a stopping portion formed at one end thereof , and an engaging member is formed on the top surface of the body . the width - adjusting spacer member is selectively arranged on the outer side walls of the body . thus , the width of the coupling mechanism can be adjusted according to the user &# 39 ; s demands , and thereby , enabling the wiper to be coupled to wiper arms having different specifications .