A breathing assistance apparatus has a housing with an engagement feature and an electrical component in the housing and a removable component. The electrical component has a receptacle. The removable component has an electrical connector that is a close or tight fit in the receptacle of the electrical component to assist with holding the removable component in connection with the electrical component. The removable component has a tab with a terminal end portion that can be flexed relative to the rest of the removable component. An engagement feature is provided on the terminal end portion of the tab and engages with the engagement feature of the housing to inhibit disconnection of the removable component from the housing in the absence of actuating the terminal end portion of the removable component to flex the tab.