Professional phone plugs in B-Gauge and MIL type design according B-Gauge standard BPO316 and MIL standard MIL-P-642/*. They are featuring similar construction as the standard Neutrik phone plugs with chuck type strain relief and slimline metal barrel to meet the high requirements for military communication equipments. These plugs are not compatible with standard 1/4" jacks (acc. EIA RS453) and patch panels.