The SBIG self-guiding filter wheel uses a positive centering mechanism that precisely re-positions filters to a precision of a few microns. This simplifies taking flats as the filter will always be brought back to the same position.
The filter wheel is designed to take 36mm round unmounted filters which will ensure no vignetting occurs with the large SBIG STT-8300. The smaller KAF-3200 and KAF-1603 chipped cameras are able to use 1.25" filters with adapter rings.
The SBIG self-guiding filter wheel attaches firmly to an STT series camera and is controlled/powered through it via the camera's I2C port.