the direct replacement is the Apollo XP95 Integrated Base Sounder with Isolator -45681-277APO. Apollo Intelligent Base Sounder 45681-265APO Intelligent base sounder installed with XP95 base attached by two M4 x 16 screws (supplied). The sounders may be connected only to control panels which use either the XP95 or the Discovery protocol. Key Features Indoor use The Intelligent Base Sounder complies with the requirements of EN54�3 2001. Mounting Instructions The Base Sounder may be secured to a UK standard conduit box or surface mounted (providing there is access through the surface for cabling). If an XP95 base is to be attached, it will be necessary to make all electrical connections, set the address, select the desired output and master/slave configuration before securing the XP95 base to the sounder. Pleae Note XP95 base not supplied with sounder.