{"product_id":"nfc-bluetooth-5-audio-receiver-rca-aux-usb-u-disk-stereo","title":"NFC Bluetooth 5.0 Audio Receiver – RCA AUX USB U Disk","description":"\u003ch2\u003eStream Music Wirelessly to Any Stereo System\u003c\/h2\u003e\n\u003cp\u003eUpgrade any wired speaker, home stereo, car audio system, or headphone into a wireless audio hub with the \u003cstrong\u003eNFC Bluetooth 5.0 Audio Receiver (Model B21)\u003c\/strong\u003e. Ultra-compact and powered via USB Type-C, it connects instantly via NFC tap or Bluetooth pairing — no built-in battery required, just plug in and play.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBluetooth 5.0 Chip:\u003c\/strong\u003e Enjoy a stable, fast wireless connection up to 33 feet (10m) with virtually zero dropouts.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNFC One-Tap Pairing:\u003c\/strong\u003e Simply tap your NFC-enabled device to pair instantly — no menus, no fuss.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDual Device Link:\u003c\/strong\u003e Pair two smartphones or tablets simultaneously and switch between them effortlessly.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMultiple Output Options:\u003c\/strong\u003e Connect via 3.5mm AUX stereo jack \u003cem\u003eand\u003c\/em\u003e dual RCA (left\/right) outputs at the same time — perfect for home stereos, amplifiers, and wired speakers.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eU Disk Playback:\u003c\/strong\u003e Plug in a USB flash drive to play MP3, FLAC, WMA, APE, and WAV files directly — no phone needed.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHands-Free Calling:\u003c\/strong\u003e Built-in microphone lets you answer, redial, hang up, or reject calls with one button. Navigation voice prompts broadcast through your speakers so you keep your eyes on the road.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAuto Power-On \u0026amp; Auto-Reconnect:\u003c\/strong\u003e Powers on the moment USB is connected and automatically reconnects to the last paired device — ideal for car installations.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e3-Button Control:\u003c\/strong\u003e Volume Up \/ Next Track, Volume Down \/ Previous Track, and a Multifunction Button for calls and playback.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHi-Fi Audio Quality:\u003c\/strong\u003e 20Hz–20kHz frequency response, 90dB SNR, and 0.1% THD deliver clean, clear stereo sound.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSpace-Saving Design:\u003c\/strong\u003e Measures just 78 × 50 × 18mm — barely noticeable, highly capable.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eB21\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBluetooth Version\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e5.0 (Protocols: A2DP, AVRCP)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eWireless Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eBluetooth + NFC\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOutput Interfaces\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e3.5mm AUX stereo, Dual RCA (L\/R)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eInput\/Power\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSB Type-C (no built-in battery)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSupported Codecs\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eSBC, AAC\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSupported Formats (U Disk)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eMP3, FLAC, WMA, APE, WAV\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFrequency Range\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e2400–2483.5 MHz\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFrequency Response\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20Hz–20kHz\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOutput Power\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e28mW (RL=16Ω)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSignal-to-Noise Ratio\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e90dB\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTHD\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0.1%\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eRange\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUp to 10m (33ft)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e78 × 50 × 18mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eWhat's in the Box\u003c\/h3\u003e\n\u003cp\u003eChoose from two package options at checkout: \u003cstrong\u003eNo RCA Cable\u003c\/strong\u003e or \u003cstrong\u003eWith RCA Cable\u003c\/strong\u003e included.\u003c\/p\u003e\n\n\u003ch3\u003eCompatible With\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eCar audio systems (non-Bluetooth head units)\u003c\/li\u003e\n  \u003cli\u003eHome stereos and amplifiers\u003c\/li\u003e\n  \u003cli\u003eWired headphones and speakers\u003c\/li\u003e\n  \u003cli\u003eHome theater receivers\u003c\/li\u003e\n  \u003cli\u003eAny device with a 3.5mm AUX or RCA input\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cem\u003eNote: This is a Bluetooth \u003cstrong\u003ereceiver\u003c\/strong\u003e only — it is not a transmitter and is not compatible with TV audio output, keyboards, or mice.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch3\u003eExplore More from Our Store\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/3-5-inch-external-cd-dvd-drives-case-sata-mini-computer-bag-external-usb-optical-drives-for-nintendo-2ds-wd-my-passport-wireless\"\u003eExternal CD\/DVD Drive Case – USB Optical Drive Bag\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/652f-60cm-usb-to-ide-3-5-2-5-hard-drive-disk-line-hdd-converter-adapter\"\u003eUSB to IDE HDD Converter Adapter Cable\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/vertical-usb-micro-usb-2-0-female-head-a-connector-2-54mm-pcb-converter-adapter-breakout-board-180-degree-vertical\"\u003eVertical Micro USB 2.0 Female PCB Breakout Adapter\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLearn more: \u003ca href=\"https:\/\/www.epa.gov\/recycle\/used-lithium-ion-batteries\" target=\"_blank\" rel=\"noopener\"\u003eEPA guidance on lithium-ion battery handling\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eQ: Does the Bluetooth 5.0 Audio Receiver work with any car stereo or home speaker?\u003c\/h4\u003e\n\u003cp\u003eA: Yes! As long as your car stereo, home speaker, amplifier, or headphone has a 3.5mm AUX input or RCA inputs, this receiver will work. Simply plug the receiver into a USB power source (such as a car USB port or USB wall adapter), connect the audio cable to your speaker system, and pair your phone via Bluetooth or NFC tap. It's compatible with virtually all non-Bluetooth audio equipment.\u003c\/p\u003e\n\u003ch4\u003eQ: Can I connect two phones at the same time?\u003c\/h4\u003e\n\u003cp\u003eA: Absolutely. The B21 supports Dual Device Link, meaning you can simultaneously pair two smartphones or a smartphone and a tablet. Both devices stay connected, and you can stream music or take calls from either one without re-pairing.\u003c\/p\u003e\n\u003ch4\u003eQ: Does it need batteries or a separate power supply?\u003c\/h4\u003e\n\u003cp\u003eA: The B21 has no built-in battery. It is powered entirely via its USB Type-C port. You can use a car's USB port, a USB wall adapter, or any USB power source rated 5V. Because it draws power directly, it also features an Auto Power-On function — as soon as power is supplied (e.g., when you start your car), the receiver turns on and reconnects to your last paired device automatically.\u003c\/p\u003e\n\u003ch4\u003eQ: What audio file formats does U Disk playback support?\u003c\/h4\u003e\n\u003cp\u003eA: When playing audio from a USB flash drive (U Disk), the receiver supports MP3, FLAC, WMA, APE, and WAV formats — covering the most popular lossless and compressed audio file types for high-quality playback without needing a connected phone.\u003c\/p\u003e\n\u003c!-- production-packaging-notice --\u003e\n\u003ch3\u003eProduction \u0026amp; Packaging Notice\u003c\/h3\u003e\n\u003cp\u003eTo maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Does the Bluetooth 5.0 Audio Receiver work with any car stereo or home speaker?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Yes! As long as your car stereo, home speaker, amplifier, or headphone has a 3.5mm AUX input or RCA inputs, this receiver will work. Simply plug the receiver into a USB power source (such as a car USB port or USB wall adapter), connect the audio cable to your speaker system, and pair your phone via Bluetooth or NFC tap. 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