It converts the 4 mm focal length TF4XA-1 HD lens to a 2.8 mm focal length while maintaining its high definition 200 cycle performance across all the sensors of 1/3-inch 3-CCD or 3-CMOS cameras.
In doing this the adapter usefully increases the horizontal field-of-view from 71 degrees to a minimum of 95 degrees. Dimensions of the Model 387 are 60.5 mm diameter and 34 mm long.
The adapter mounts onto the TF4XA-1 via the 30.5 mm external thread on the front of the lens. The Model 387 wide angle adapter has an M60 x0.5 thread on the front to facilitate the mounting of filters.