World class noise cancellation makes quiet sound quieter and music sound better; Connectivity Technology: Wireless. Volume optimized EQ for balanced audio performance at any volume. Wireless convenience, with easy Bluetooth and NFC pairing aided by voice prompts. 20 hour battery life per charge; up to 40 hours in wired mode. Noise rejecting dual microphone system for clear calls even in windy environments; Headphones:18 cm H x 17 cm W x 8.1 cm D (0.52 lb/234 g). Your business is greatly appreciated. Due to our high volume of requests we are unable to respond to best offers if they are not acceptable. We are not responsible for any damages/losses through the use of the items / services rendered. For your protection and ours, security stickers are added to all products and serial numbers are recorded. We will do what we can to deliver your order by date required. For your protection and ours all items are supplied with security tags and all serial numbers are recorded.