This is a receiver that easily makes your earphones and headphones wireless. It has a built-in microphone and supports hands-free calls. From the official website: USB power supply, microUSB input terminal Bluetooth standard Ver. 5.3 Music playback time: Approximately 9 hours (50% volume) Talk time: Approximately 9 hours (50% volume) About the item: Purchased from a mass retailer for about 1200 yen around September. I'm selling this because the headphones I usually use are a special type and didn't produce any sound. I'd like to clear them out. Normal earphones and the like work perfectly fine. Condition: Used only once, in almost new condition. It should work with most headphones and earphones, unless they are very unusual. Other: It's much smaller and has better battery life than receivers from Sony and other companies from the past.