IEC 61300-2-33:2012 is a part of a series that evaluates the assembly and reassembly of a fibre optic mechanical splice, a fibre management system or a closure for a specified number of times. This third edition cancels and replaces the second edition published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: the inclusion of fibre management system and ancillary passive and active components as well as cable management system for the incoming and outgoing optical cables. Key words: fibre optic mechanical splice, fibre management system or a closure