The SVBONY SV550 is an 80mm f/6 apochromatic refractor optical tube (OTA). Its air-spaced triplet uses one S-FPL51 low-dispersion ED element and two correction elements to control chromatic aberration for bright, high-contrast views of galaxies and Messier objects such as M42 and M45. It has a 2.5 inch magnesium alloy dual-speed (1:10) focuser and four internal light barriers to cut stray light.