SV133 is ideally suitable for visual observations with 1.25" eyepieces; And with the included T2 adapter it is also perfectly suitable for astrophotography with single lens reflex cameras and CCD cameras; The included T2 adapter comes with a locking ring; whereby high-precision distance regulation becomes possible | This 1.25" filter wheel lets you use up to 5 different filters and change them within just a few seconds;Filter positions indicated by the numbers 1-5;simply note the reference number of each filter during installation;then rotate the knurled wheel until the desired number is displayed in the small notch in the filter wheel housing | It’s very sturdy aluminum housing makes it also suitable for heavy cameras; The filters can be changed very quickly at any time; even with the camera mounted or with the eyepiece inserted;With 42mm metal dust cap, you can also leave your filters mounted in the filter wheel;as they are optimally protected from dust and damage there | The robustly constructed filter wheel is supplied with a 1.25" eyepiece adaptor; 1.25" focuser nosepiece;T-2 camera adaptor and locking ring;allowing you to quickly and easily attach it to your focuser;The very short design also permits the use of devices with short back focus such as Newton or Dobson telescopes | The filter wheel interior is absolutely light-tight - allowing you to image without any reflections or stray light;It's construction is impermeable to light and thus ensures reflection-free astrophotography