Used on san/bqs-15 unit 2, projector assembly;an/bqs-15 units 4/5, receiver canis;an/bqq-10(v) unit 4802, projector assy;an/bqq-10(v) unit 4803, hf array basi;an/bqs-15a unit 2, projector assembly;an/bqs-15a units 4/5, receive canister. 0.750" hole diameter navy) washer, flat .75 titanium 5