The focuser is attached to every telescope near the focal point of the light-gathering optics. As the name suggests, eyepieces can be inserted into the focuser. For astrophotography, focusers hold cameras and bring them into focus. This is why they are also referred to as focusers instead of eyepiece focusers.
This rack and pinion focuser is for all amateur astronomers who needs a bigger focuser than 2" which should be compact. The focuser especially offers a better illumination, needed for working with larger sensors. With 88.9 mm, the travel range is generous. The focuser is popular with refractor of moderate speed from f/7 downwards.
Currently, this focuser is praised as a better alternative to 2" focusers.
