Answer
There are 3 lens variants for ceiling occupancy/vacancy sensors (and applies to both dual tech and non-dual tech). They all use the same hardware except the lens installed in the sensor is different. The difference can only be seen from the underside of the lens. See below for images and descriptions:
High Ceiling

Large Room/2000 sq ft coverage
- Series of linear striations, may be difficult to see visually but can feel very easily

Small Room/500 sq ft coverage
- Combination of both above, with series of circles with rippling striations
