Takahashi 2" Adapter for FS-102/128/130/152

Product Overview

Takahashi's 50.8 Adapter for Normal Refractors (TKP27110) is the ring that lets an FS-102, FS-128, FS-130 or FS-152 take standard 2-inch eyepieces and diagonals. These four telescopes share a 2.7-inch drawtube, and a bare 2-inch barrel simply won't fit it without this step-down in between.

Takahashi publishes a light path length of 40 mm for the adapter — not its physical size, but what it adds to the train once it's threaded on. At 40 mm it's a meaningful chunk of spacing, worth accounting for if you're already tight on focus travel or working out backfocus for a flattener downstream.

Who It's For

This is a good match if you own an FS-102, FS-128, FS-130 or FS-152 and want to run 2-inch eyepieces or a 2-inch diagonal on it.

It won't help on other Takahashi models, though — the FSQ-85ED and FSQ-106EDX4 use the same M72 thread but a shorter, 30 mm version of this adapter, sold separately.

Key Features & Design

• M72 x 1.0 male telescope-side thread: fits the 2.7-inch drawtube of the FS-102/128/130/152 series.
• 2-inch (50.8 mm) accessory side: accepts standard 2-inch eyepieces and diagonals.
• Purely mechanical: a step-down ring, with no optical element and no effect on focal length or focal ratio.

Recommended Uses

• Visual observing with 2-inch wide-field eyepieces on the FS-102/128/130/152.
• Fitting a 2-inch star diagonal, for the wider true field it gives over 1.25-inch.

Compatibility and Accessory Notes

• Built for the FS-102, FS-128, FS-130 and FS-152 and their shared 2.7-inch drawtube — it isn't a universal 2-inch adapter.
• Adds 40 mm to the optical path. That's the figure to weigh against your focuser's inward travel and against any flattener's backfocus spec down the line. Our Takahashi Back Focus Guide lists it alongside the back focus each telescope needs.

Good to Know Before You Order

• It's specific to the 2.7-inch drawtube telescopes named above. Tell us your FS model if you're not sure which drawtube it uses and we'll confirm.

Frequently Asked Questions

Is it difficult to set up?

No — it threads onto the drawtube and the 2-inch accessory slides straight in.

Which telescopes does it fit?

The FS-102, FS-128, FS-130 and FS-152, which all share a 2.7-inch drawtube.

How much does it add to my optical train?

40 mm, and that's worth checking against your focus travel before you order — send us your setup and we'll confirm it fits.

Does it work on the FSQ-85ED?

No — that telescope takes a shorter version of this adapter, at 30 mm of light path, sold as its own part.

Bottom Line

In short: a 2-inch adapter for the FS-102/128/130/152's 2.7-inch drawtube, adding 40 mm of light path to the train.