SPECIFICATION: MEDIUM NOISE ATTENUATING PER MIL-H-83511. PRODUCT: MIL-DTL-83511. CABLE: APPROXIMATELY 24 INCHES TERMINATED WITH A U-174/U CONNECTOR. COLOR: BLACK. MICROPHONE: M-87/AIC (5 OHM) PER MIL-PRF-26542/1 OR OPTIONAL BOOM MOUNTED MICROPHONE M-101/AIC PER MIL-PRF-26542/4 (5 OHMS) . EARPHONE: 2 EA. H-143/AIC PER MIL-E-25670 (19 OHMS).