This is the RK-BT100A, a USB Type-A compatible Bluetooth transmitter. The "RK-BT100A (USB Type-A connection)" operates as an audio device when connected to compatible devices such as smartphones, PCs, and game consoles equipped with a USB Type-A connector. It's a dongle-type Bluetooth audio transmitter that wirelessly transmits audio information to Bluetooth headphones and other audio devices. It supports low-latency codecs "aptX/aptX LL," dramatically improving synchronization between the visual media and audio output of compatible devices. Included are the main unit and instruction manual. Operation has been confirmed, but compatibility is not guaranteed depending on the combination of devices. This item was functioning normally until removed. It is a used item stored at a private residence, and returns or refunds will not be accepted if it does not function in the buyer's environment. Reference: Manufacturer's product website https://www.radius.co.jp/products/rk-bt100a/?srsltid=AfmBOopp9LHok9NqDUN-uK6ZE65Q7E8Qptoqrys0_buS727Tzmr7xtSA 【Important】 The exterior appears to be in good condition without any noticeable scratches (in my subjective opinion). However, as this is a used item, there may be some minor scratches or scuffs if examined closely. It is sold as-is. Please refrain from purchasing if you are concerned about the details of the condition.