| This adapter converts a refractor or reflector's 2" focuser drawtube to a standard Schmidt-Cassegrain 2" rear cell thread. This allows you to use SCT accessories (eyepiece holders, tele-extenders, T-adapters, off-axis guiders, etc.) with those refractors and reflectors that have a 2" rack and pinion or Crayford focuser drawtube. It also allows you to use SCT accessories with an SCT that has an add-on 2" external focuser, such as a Feather Touch, that does not come with an SCT rear cell thread.
The side of the adapter that fits into the focuser drawtube has a 2" barrel. The sides of the barrel are smooth, with no safety shoulder or groove for the compression ring or thumbscrew of your focuser to grip, so be certain you tighten down the focuser very firmly before trusting the weight of a heavy diagonal and eyepiece or heavy photo accessories to this adapter.
The opposite side of the adapter has a short barrel with a male 2"-18 thread that duplicates the normal rear cell thread of a Schmidt-Cassegrain telescope. This allows you to use any SCT-threaded accessory with a 2" drawtube rack and pinion or Crayford focuser.
The body of the adapter is made of machined aluminum, anodized black for long life.
If you stack SCT accessories on a reflector (and to a lesser extent on a refractor), make certain that you have enough focuser in-travel to reach focus with the SCT accessories in place.
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