The OPTEC-4300 25mm Extension Ring provides approximately 1-inch of extension for any OPTEC-4300 telescope adapter. Ideal for telescopes where the Gemini Focusing Rotator may need to pushed out and away from the OTA to provide clearance for cooling fans or when a little extension is required to reach optimal focus.

Any OPTEC-4300 telescope adapter.
Gemini Focusing Rotator.
TCF-Lynx3 3-inch Focuser.

Inside Diameter: 3.9" (99mm)
Outside Diameter: 4.95" (126mm)
Overall Height: 1.30" (33.2mm)
Clear Aperture: 3.9" (99mm)
Weight: 8.8 oz (250 g)
Back-Focus Usage: 0.984" (25mm)

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#19839 - OPTEC-4300 Extension Adapter, 25mm length.

Quantity

In Stock: 6