Left-BUD Gold Earphone Utilizes patented 1-BUD technology to mix the Left and Right stereo sound channels into a single earpiece for the Left ear Earphone is held in place by a curved, flexible rubber loop that comfortably keeps the earpiece positioned in your ear Has a 1/8-inch size 3.5mm gold-plated plug, 4ft cord, compatible with most devices Enables users to safely keep one ear open to surrounding activities while listening to audio Very popular for those with single-sided deafness (SSD) and those who have a hard time keeping an earphone in their ear