The glass used with prompt-it® Teleprompters has dual view with reflection and transmission of light. 70% light transmission and 30% reflection (70T/30R). It has an optical thin-film coating on one side that reflects and transmits light waves that fall upon it at a specific ratio. prompt-it® beamsplitter glass is high quality and true-to-source colour of both reflected and transmitted light. prompt-it® beamsplitter glass is also specially designed both for interior and exterior applications. The process to create this special glass is complicated and time-consuming, therefore it is expensive and should be treated with care (like your camera lens).