3300 XL 8 mm proximity probe, 06: Probably the option of unthreaded length (e.g. 60 mm)., 12: Probably the overall length option of the enclosure (e.g. 120 mm)., 20: Probably the total length option (e.g. 2.0 meters)., 02: Connector option and cable type (for example, standard cable without armor and standard connector)., 05: Agency approval option (e.g., specific approvals such as CSA/ATEX, although "05" may indicate another specific option).