4 點矩形標準安裝模式指示符，帶孔安裝方法的支架

An_enclosure_which_includes_mounts，_and_protects_such_items_as_switches，_circuit_breakers，_jacks，_fuseholders，_connectors，_terminals_and/or_terminal_boards，_resistors，_capacitors，_transformers，_and_the_like._it_is_primarily_designed_to_distribute_electrical_power_from_one_or_more_primary_power_source（s）_such_as_generator（s）_and_battery（ies）_to_one_or_more_electrical_and/or_electronic_item（s）._it_may_include_a_cover_or_door._for_enclosures_which_include_only_circuit_breakers，_switches，_jacks，_fuseholders，_terminals_and/or_terminal_boards，_see_circuit_breaker_box;_switch_box;_jack_box;_fuse_box_and_terminal_box._for_enclosure_primarily_designed_to_interconnect_two_or_more_electrical_and/or_electronic_items，_except_primary_power_source（s）_see_interconnecting_box._for_empty_boxes_which_are_designed_to_mount，_but_do_not_include_electrical_devices_such_as_switches，_插孔，_fuseholders，_terminals_and/or_terminal_boards，_see_junction_box._see_also_interconnecting_cabinet;_control_（as_modified）;_panel_（1）_（as_modified）;_relay_assembly;_panel，_power_distribution;配電盤（修改後）和面板、保險絲。不包括：連接器開關。