This is a large 3.7", dual speed, rack and pinion focuser. This imported focuser was used on some of our earilier models of 130mm and 152mm refractors. The 130 tube model threads to a tube that has a male M139X1 thread and the 152 model threads to a tube using a male M156X1 thread. We also have some focusers that have a male thread that will thread into a female thread that is M124X1. The male threadon this focuser is about 7.7 mm width. The dual speed mechanism has a 9.5-1 gear ratio. The drawtube has about 98 mm of travel. The focuser is fully rotating with 3-5 bearing surfaces and thumb screws are used to adjust tension. This is new-old stock we have had in storage.
