This is the large reducer flattener that is made for our new SVX152T refractor. This version has adapters and extensions optimizing it for use with a DSLR equipped with a large 48 mm t-ring or a CCD/CMOS astronomy camera with a 55 mm back focus using an M48 attachment thread (such as ZWO cameras). If your camera has a different thread size or back focus call us and we can generally modify the parts supplied to meet your requirements.