Wireless earphones with a waterproof design and a 27-hour battery life, featuring a BASS BOOST function. I am selling these because I received a brand new pair of "Sennheiser MOMENTUM True Wireless 4" from a friend as a gift, so I no longer have a need for them. They are in beautiful condition. All accessories are included, including the box. I have confirmed that they are working properly and there are no malfunctions. I have used them, but there are no noticeable scratches, and the number of times I used them is: - 1-2 hours per use - About 10 times For personal preference, I was using "AZLA SednaEarfit XELASTEC II Standard" ear tips. These are recommended ear tips, and I will send them attached. All of the included ear tips (all unused) will be included, so please replace them as you like. I have cleaned both the main unit and the ear tips with alcohol. Please refrain from purchasing if you are concerned, as these are used items. Also, I do not accept price negotiations. Thank you for your understanding. - Brand: Sennheiser - Model Name: CX True Wireless - Features: Waterproof - Battery Life: 27 hours - Accessories: Charging case, USB cable, ear tips - Sound Quality: BASS BOOST Thank you for looking.