1.1 Product definition This document contains the initial, start of life, dimensional, optical, mechanical and environmental performance requirements that an assembled single mode cord with cylindrical ferruled connectors will meet in order for it to be categorized as an EN standard product. Since different variants and grades of performance are permitted, product marking details are given in 4.5 and Clause 5. 1.2 Intermateability of the plugs Where the products conforming to the requirements of this document are intermateable, the resulting level of random attenuation performance will be in accordance with Table 1. The intention is that this will be true irrespective of the manufacturing source(s) of the product. When intermating plug variants having different attenuation grades (as specified in EN 61755-1) the resulting level of attenuation cannot be any better than the worst attenuation grade of the individual plugs. Intermating a grade C plug with a grade B plug will result in a grade C level of random attenuation performance. Table 1 Attenuation grade matrix 56 Plug 1 grade Plug 2 grade Ensured attenuation grade B B B C C C B C C C B C 1.3 Operating environment The tests selected, combined with the severities and durations, are representative of an EN 61753-1 Category C environment. 1.4 Reliability Whilst the anticipated service life expectancy of the product in this environment is 20 years, compliance with this standard does not guarantee the reliability of the product. This should be predicted using a recognized reliability assessment program. 1.5 Quality assurance Compliance with this standard does not guarantee the manufacturing consistency of the product. This is expected to be maintained using a recognized quality assurance program.