Abstract: A remotely operated plug unit (13) for use in a sink or basin (12) with a sink waste unit (11). The drain pipe requires minor modification, by the insertion of two holes (18, 19) opposite one another part way down the threaded sides (17). The plug (13) is spring biassed to an open position and retained in a closed position by two pins (31, 34). The second pin 34 is remotely activated (by cabling (14)) by an actuator (44) and opening mechanism (15). The plug (13) is closed manually by direct downward pressure on the top of the plug (13). All components for operation of the plug (13) which are contained within the sink waste unit (11) are circumferentially positioned. Three preferred embodiments of the opening mechanism (15) are disclosed (two being capable of incorporation in a tap for the sink (12)). Various embodiments in the manner of operation of the plug (13) are also disclosed.