The SV231 color correction filter is designed with full thread and standard size to compatible with different types of telescope. High transmittance means high level of transparency, allows a significant amount of light or energy to transmit through it. You can use the SV231filter with SV48P telescope for astronomical observations without color difference to obtain the most exquisite details of lunar craters and planetary surfaces. SV48P telescope features with 2-1.25 inches adapters which is compatible with all 1.25" and 2" accessories such as eyepieces, Barlow lenses, zenith mirrors. Relax the conditions for choosing accessories, making it easier for you to match accessories. The gear ratio of the 2-inch rotatable double-speed focuser is 1:10, so that it is easy to achieve accurate focus. The gear ratio of the dual speed 2-inch toothed focuser with a reduction ratio of 1:10. A combination of constant-speed and fine-speed, making it easy to achieve precise focus.