The new Industrial Ultra Series from RigdeLine features DLSCâ„¢ technology, which gives instant, 1.7 millisecond hearing protection from damaging noise levels while enabling the user to maintain complete awareness of the work environment. Talk-Thru Audio Technologyâ„¢ lets the wearer hear all sounds, all the time, while being protected. Pro-Form Leatherâ„¢ Ear Seals offer reduced ear seal pressure.RidgeLine, Inc., Westcliffe, CO.