1. This device enables long-distance one-way audio transmission (two sets required for duplex intercom functionality) and can transmit audio signals from sources such as mobile phones or MP3 players, with audio received at the receiving end. 2. The system operates on the principle of infrared laser sound transmission, converting sound fluctuations into a red laser beam. The laser signal is captured by a photodiode receiver in the receiving circuit and demodulated to restore the original audio. 3. Transmission range reaches 50-100 meters, suitable for creating long-distance wireless speaker setups. Series: Laser Wireless Audio Transmission Kit Model: Laser Wireless Audio Transmission Kit Fun Electronic Production DIY Electrical and Electronic Teaching Training Parts Application: Laser Wireless Audio Transmission Kit Electronics Series Electronic Technology Package: Parts Color: Green Material: Plastic Size: 4x2.2cm Package Contents: 1 x Laser Wireless Audio Transmission Kit Note: Light reflection and variations in display settings may cause slight differences in the color of the item as shown. Measurement error allowance is +/- 1-3cm.