S8171 astronomical telescope RC8 and RC6 dual speed toothed focusing M90x1 high-quality 2.5-inch flat field

S81712 inch dual speed toothed focusing
Suitable for GSORC8 and RC6, as well as brands manufactured by GSO
Thread size: M90x1
Focusing stroke: 35mm
Dual speed with teeth, 1:10
360 degree rotation support
Flat field, M54 * 0.75 in front
The output terminal is M48 * 0.75
Rear intercept 55mm