Original Genuine Xpand X-Battery For X101 X102 Active DLP-Link 3D Glasses (Four (4) X-Battery, One (1) Battery Key) XPAND battery comes in a case that makes it waterproof and easy to replace (using the Battery Key) 120 hours for DLP-Link glasses 250 hours for X101 glasses Please note: When storing the glasses for longer than one week, it is advisable to remove the battery to maintain the battery life.