Interconnection • 1.3m (4.25ft) cables, End with a gold-plated 3.5 mm (0.14 inch) rectangular gold-plated stereo plug certificate and approval certification European CE technical specification of electrical impedance each receiver 32 ohms audio frequency response 20 Hz to 20 kHz (+ / - 3 dB) capacity of 30 mW power amplifier (1 kHz) of 111 dB SPL/receiver sensitivity (each receiver 1 mW) mechanical 56 grams (0.12 pounds) of weight paint carbon black (PH10736) and silver order information HDP LWN portable neck band earphones lightweight neck band earphones can reproduce high-quality sound with replaceable earplugs. HDP-LWNEP earplugs in hardware accessories of order no. Order number HDP - LWNE