Sennheiser use to make excellent product . they `` improve '' they line of wireless rf headphone so that now it be very difficult to use and produce poor sound quality -- and , as a bonus , fail to work at all more often than not . because I be very busy , I keep the product too long to return . I would be please if Amazon would let I return it for a refund -- and maybe even help I find one of Sennheiser 's old , excellent product .