The #17816 3-inch Adjustable Extender Tube adds anywhere from one to three inches of back-focus to your optical setup by making use of V-grooves that are set at multiple points along the body of the tube. The back of the tube presents an OPTEC-3000 dovetail to attach to any product with an OPTEC-3000 receiver, including the TCF-S3, IFW-3, and Pyxis 3" rotator.
- Outside Diameter: 3.56" (90.4mm)
- Overall Height: 4.5" (114.3mm)
- Clear Aperture: 2.65" (67.3mm)
- Weight: 12.48 oz (353.8 g)
- Back-focus Usage: 1-3.1" adjustable (25.4-78.7mm)
- Telescope Side Connection: 3" Adjustable V Groove
- Camera Side Connection:: OPTEC-3000 Receiver