The GCM-09120 series Glan-Taylor prism adapters are specifically designed to clamp our company's Glan-Tatlor prisms, connecting them to waveplate mounts for rotational use. Among them, the GCM-091203M has a larger diameter, which may easily block the dial. Therefore, it is necessary to select polarizers/waveplates with side markings, such as connecting to the GCT-090132 or the GCM-1109M rotating mount with a larger turntable for use.