try this place this seems the right base for your detectors you could ring the manufactures to check that they are compatible then you might be able to order 1 direct from them or they might tell you there distributers
http://www.sdfirealarms.co.uk/shop/...withrelay-p-479.html?cPath=33_143_146_166_169
G.T.S![Cool :cool: :cool:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
http://www.sdfirealarms.co.uk/shop/...withrelay-p-479.html?cPath=33_143_146_166_169
G.T.S