Califone HPK-1520 Titanium Series Headphones Softer, more comfortable ear cushions Comfort strap for longer wear ability Adjustable head strap rugged enough for daily classroom use Ear cups offer the highest passive ambient noise rejection, effectively blocking external distractions to keep students on task In-line volume control, LED light is green when the cord is plugged into the computer and red when the Sentinel switch is turned on Connectivity technology: Wired