ASTRO-TECH (GSO/iOptron/MallinCam/Orion/TPO) RCT Series

We offer knobs for the Astro-Tech, GSO, iOptron Photron, MallinCam VRC, Orion (US), and TPO OS 6”, 8”, 10”, 12”, and 16" Ritchey-Crétien secondary. Select knobs for your telescope from the list below. Price is for a complete set of knobs.

A. Knobs for Astro-Tech (GSO/iOptron/MallinCam/ Orion/TPO) 6" f/9 Ritchey-Crétien Secondary
AT8RC

Part: AT6RC
Fits: Astro-Tech, GSO, iOptron, MallinCam, Orion (US), and TPO 6" f/9 RCT secondary (solid or truss-tube)

Knobs: Black plastic, 16 mm (5/8”) diameter
Threads: Stainless steel

Notes:
  1. If the dust cover cannot be installed because of knob height, you can use a shower cap in its place.

$25.95

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B. Knobs for Astro-Tech (GSO/iOptron/MallinCam/ Orion/TPO) 8" f/8 Ritchey-Crétien Secondary
AT8RC

Part: AT8RC
Fits: Astro-Tech, GSO, iOptron, MallinCam, Orion (US), and TPO 8" f/8 RCT secondary (solid or truss-tube)

Knobs: Black plastic, 16 mm (5/8”) diameter
Threads: Stainless steel

Notes:
  1. If the dust cover cannot be installed because of knob height, you can use a shower cap in its place.

$25.95

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C. Knobs for Astro-Tech (GSO/iOptron/MallinCam/ Orion/TPO) 10" f/8 Ritchey-Crétien Secondary
AT10RC

Part: AT10RC
Fits: Astro-Tech, GSO, iOptron, MallinCam, Orion (US), and TPO 10" f/8 RCT secondary (solid or truss-tube)

Knobs: Black plastic, 16 mm (5/8”) diameter
Threads: Stainless steel

Notes:
  1. The factory dust cover may contact the knobs when installed, but the cover will remain in place. If desired, a shower cap can be used as a substitute cover.

$25.95

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D. Knobs for Astro-Tech (GSO/iOptron/MallinCam/ Orion/TPO) 12" f/8 Ritchey-Crétien Secondary
AT12RC

Part: AT12RC
Fits: Astro-Tech, GSO, iOptron, MallinCam, Orion (US), and TPO 12" f/8 RCT secondary (solid or truss-tube)

Knobs: Black plastic, 16 mm (5/8”) diameter
Threads: Stainless steel

Notes:
  1. The factory dust cover will fit normally with Bob’s Knobs installed.

$25.95

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E. Knobs for Astro-Tech (GSO/iOptron/MallinCam/ Orion/TPO) 16" f/8 Ritchey-Crétien Truss-Tube Secondary
AT16RC

Part: AT16RC
Fits: Astro-Tech, GSO, iOptron, MallinCam, Orion (US), and TPO 16" f/8 RCT truss-tube secondary

Knobs: Black plastic, 16 mm (5/8”) diameter
Threads: Stainless steel

$25.95