IEC 61755-3-6:2006+A1:2012 defines dimensional limits and material properties of a 2,5 mm and a 1,25 mm diameter cylindrical composite ferrule optical interface to meet specific requirements for APC fibre-to-fibre interconnection. This consolidated version consists of the first edition (2006) and its amendment 1 (2012). Therefore, no need to order amendment in addition to this publication.