2.4GHz uncompressed wireless signal transmission for noise-free, low-latency performance. (Nominal transmission distance: 30-40m, Charging time: 4 hours, Continuous use time: 15 hours) *Please note that the outer box may show signs of wear, but the contents are new. *Due to the size (thickness) of the box, the box will be folded and the product will be packaged with cushioning material for Yu-Packet Mini delivery to reduce costs (= save on shipping). (There may be scratches or damage on the folded outer box) 【Important Notice】 Recently, some customers have exhibited the unreasonable expectation that if they don't like the sound quality after purchase, they can return the product as if it were defective. Please note that returns after testing are possible on Amazon, but this is not an Amazon marketplace. If you are looking for high-quality sound, we strongly recommend the "BOSS Guitar Wireless System WL-50" (Amazon price: ¥29,700). This product also comes with a one-year warranty! What are you expecting from a product that costs only about one-fifteenth of the price...? Of course, we will accept returns for products that do not transmit or receive signals properly...