ICL provides inexpensive KBr cover slips for samples heated in highly pressurized chambers by CO2 lasers to liberate entrapped gases such as Argon from minerals and other natural samples for 40Ar-39Ar dating using a mass spectrometer. KBr is the material of choice for this application since KCl and NaCl tend to release chlorine which can damage an expensive mass spectrometer. Common choices for this application are our 41 x 3mm KBr cover slip windows Part No. 0002C-9343. Other sizes are available; inquire for pricing.