What is the difference between the 2 black masks for the SDR, the SDR-OSM24 and SDR-MSV24?

• The SDR-OSM24 (Optical Shielding Mask) is used with deep well plates. It prevents sample fluorescence in bacterial or yeast cultivations from disturbing the oxygen or pH measurements. It is made of aluminum and put between the SDR and the deep well plate.
• The SDR-MSV24 (Mask for SensorVials) is used with SensorVials (2 mL or 4 mL format). It prevents artificial light used for photosynthesis measurements from disturbing the oxygen readings. It is made of plastic (POM) and put on the SDR. The SensorVials are placed into the wells of the mask so they are held in position above the SDR's optics.