This is the Sennheiser Momentum 4. I purchased it on Amazon this April and wore it a few times, but I'm selling it because I use other earphones more often. The color is copper, a limited edition from Amazon. It comes with the BTD600, so the sound quality is better than a Bluetooth connection when connected. The headset seal has been removed, and there are some signs of use, but I think it's in good condition. It's currently selling for 55,000 yen on Amazon, so please consider it if you're thinking of buying new, even if it's used. Please understand that this is a used item, so there may be minor imperfections.