These Class 4 CO2 laser safety glasses comfortably fit over prescription glasses or can be worn alone. They offer OD 7+ protection from 10600nm infrared light. They are necessary for Class 4 laser operation, for example cutting materials that are not Proofgrade with the Glowforge Pro. They are not required for the Glowforge Basic or Glowforge Plus. They may also be used with other lasers.