Barr & Stroud/Lasergage. Helicopter infra red system Barr & Stroud. Pacesetters Barr & Stroud. chalcognenide glass type I, For optical elements in infra red systems Barr & Stroud. Data sheet, Passive night telescopes CU17 and CU18 Barr & Stroud. Calcium aluminium glasses, For infra red optics G.E.C. High intensity runway light G.E.C. Low intensity appraoch light ATM. Street fire alarm and ambulance systems. ATM. Electro-matic vehical actuated signals, pneumatic type detector ATM. Strowger, Ten-line private automatic telephone exchange equipment ATM. Strowger 25-line private automatic telephone exchange equipment ATM. Rythmatic control, Type 45 equipment for l.t. substation areas, engeneering bulletin 2191