IEC 62339-1:2006 establishes properties and physical dimensions that define the interface for surface-mount fluid distribution components with elastomeric sealing devices used within process analyser and sample-handling systems. The interface controls the dimensions and location of the sealing surfaces to allow change of just one element of the system without modification of the entire system. This is what makes the system modular from both a design and a maintenance standpoint. It cancels and replaces IEC/PAS 62339-1 published in 2003. This first edition constitutes a technical revision.