The Sennheiser RS 135 Wireless Headphone Battery will solve your battery problems or provide you with a spare battery. The Sennheiser RS 135 Wireless Headphone Battery comes with a 30-day money back guarantee and a 1-year free replacement warranty. Once we have received your new order for the Sennheiser RS 135 Wireless Headphone Battery, it will be processed within 24 hours or on the next business day with Free Shipping via USPS First Class Mail.