#17839 - OPTEC-4300 Extension Ring, 25mm.
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.
|Inside Diameter:||3.9" (99mm)|
|Outside Diameter:||4.95" (126mm)|
|Clear Aperture:||3.9" (99mm)|
|Weight:||8.8 oz (250 g)|
|Back-Focus Usage:||0.984" (25mm)|
- Any OPTEC-4300 telescope adapter.
- Gemini Focusing Rotator.
- TCF-Lynx3 3-inch Focuser.