Sky Watcher Esprit 120ED Reducer/Flattener .77x. 85x Reducer/Flatteners to your 120ED or 150ED telescope. The adapter also allows you to easily rotate your imaging train 360 degrees without removing anything from the optical system. This reducer also features a built-in 2" filter mounting enabling you to easily place filters into the light path. This adapter is provided as a standard with all new Sky-Watcher DS optical tubes. If you own an DS or DS Advanced you will want to also grab the DSAdapterAdapter2 that is also included with the DSAdapter2. This adapter offers the full range of DS performance with the added benefit of a Reducer/Flatteners ability to thread on and off easily without damaging the threads. This reducer/flattener is also a great add-on for boosting the magnification on your DS or Advanced DS telescope. Specifications for Sky Watcher Esprit 120ED Reducer/Flattener: Manufacturer: Sky Watcher Condition: New Additional Features: 55mm Back Focus with M48 Thread Three-element Design Color: Black Weight: 920 g Model: 120ED Focal Ratio: f5.4 Fabric/Material: Aluminum Optical Coating: Fully Multi-Coated Features: Allows Evostar 0.85x Reducer/Flatteners to easily adapt to your Evostar ED telescope Provides a secure threaded connection Allows you to rotate your imaging train 360 degrees without removing anything from the optical system Built-in 2" filter mounting to easily place filters into the light path Compatible with: Evostar 80ED 100ED 120ED and 150ED (not the 150DX). Package Contents: Sky Watcher Esprit 120ED Reducer/Flattener Sky Watcher S20209: Esprit 120ED Reducer/Flattener .77x