Suitable for use with brown IRT and Welch Allyn Thermoscan tympanic thermometer. Used properly, these covers can help prevent cross infection. Suitable for Braun IRT and Welch Allyn Thermoscan thermometers, including: Welch Allyn pro 3000, welch Allyn pro 4000, from Welch Allyn brown irt4520 thermometer Prevents cross-infection.