What sensor size does this lens fit?

It is made for 1/1.8-inch sensors, where it covers up to 6–8MP. On smaller sensors the image circle is wasted and the field of view narrows further.

What field of view does an 8mm lens give?

On a 1/1.8-inch sensor the 8mm focal length is a medium telephoto, noticeably tighter than the 2.8–4mm lenses common on security cameras. Expect to cover a doorway or a distant subject, not a whole room.

Is it glass or plastic?

It is a hybrid design, mixing glass and plastic elements. That is what keeps it compact and low-cost, but it is not an all-glass lens.

Does it fit a standard M12 mount?

Yes, it uses the M12 (S-mount) thread found on many board cameras and camera modules. Check that your module's sensor is 1/1.8-inch before buying.

Is it suitable for low-light use?

The specification does not state an aperture, so low-light performance depends on your sensor and lighting. A larger sensor and good illumination matter more than the lens here.