Colourful inner-ear headphones with Bluetooth Wireless Technology. Manufacturer: Victor Company of Japan, Limited. Manufacturer Part Number: HAFX21BTB. Brand Name: JVC. Product Model: HA-FX21BT. Product Name: In Ear Headphones HA-FX21BT. Package Type: Retail. Packing: Box. Product Type: Earset. [Technical Information] Connectivity Technology: Wireless. Wireless Technology: Bluetooth. Wireless Operating Distance: 32.8 ft. Sound Mode: Stereo. Minimum Frequency Response: 20 Hz. Maximum Frequency Response: 20 kHz. [Earpiece] Earpiece Design: Earbud. Behind-the-neck. Earpiece Type: Binaural. Driver Size: 0.32". [Microphone] Microphone Design: On-cable. [Physical Characteristics] Color: Black. Form Factor: In-ear. Weight (Approximate): 0.39 oz. [Miscellaneous] Package Contents: In Ear Headphones HA-FX21BT S/M Silicone Earpieces USB Charging Cord .