CHxxx

Please can anyone help me. I recently bought a swan gas cooker sx1030. When the man came out to fit it he said we needed a half inch bsp fitting, as my cooker came with no manual does anyone know what type of half inch bsp fitting I may need? I've searched online but there is so many of them I haven't got a clue which one I'll need. Any help would be very much appreciated. Thank you in advance.