Featuring an aluminum frame with small built-in magnets, the Clear Quartz Dust Protective Magnetic Clip-In Filter for Sony E from Kolari Vision secures magnetically to the camera lens mount, and your lens then mounts on top. The filter sits securely between the camera and lens. It's compatible with full-frame Sony E-mount cameras.
When used with an unmodified camera, this filter works as a protective filter to just cover the sensor. But it's mainly intended for use with full-spectrum modified cameras to let in IR and UV light. A full-spectrum modified camera is one in which the camera's native low-pass filter was removed and replaced with a clear filter. (Kolari Vision can make the modification for you at a cost if you send in your camera to them.)
A third use is for "naked" cameras — those that are modified but not fully, those that have the camera's native low-pass filter removed but a replacement clear filter not added in place. In this third use, this clear quartz filter functions as the replacement filter and allows for clear focusing.
The filter material is glass. A small removal tool is included but not required. The compact tool looks like a guitar pick and is included just in case, as the filter can easily be removed by hand.