Takahashi 2 Inch Sleeve Adapter

Product Overview

Takahashi's own catalog designation for this part is the "50.8 Sleeve" — a short ring in the 50.8 mm (2") accessory system with a published light path of 5 mm, the shortest spacer in the Takahashi accessory line.

Who It's For

This is a good match if your Takahashi system chart calls out this ring within a 2" accessory chain, or you're replacing this specific part from an existing setup.

Key Features & Design

• 50.8 mm (2") sleeve fitting: Takahashi's own "50.8 Sleeve" designation for this ring.
• 5 mm light path: a small, fixed increment for fine-tuning spacing rather than bridging two different standards.
• Takahashi part TKP00113 — a single-piece machined ring with no moving parts.

Recommended Uses

Use it where a Takahashi system chart specifies this part within a 2" visual or imaging train, typically to add a small, fixed amount of spacing.

Compatibility and Accessory Notes

Takahashi's catalog lists this ring as the "50.8 Sleeve," with a 5 mm light path — what it contributes to the optical train, not a caliper measurement of the part itself. It's a sleeve fitting rather than a thread adapter, and Takahashi doesn't spell out a separate 2"-to-1.25" step-down for this part number. If your train needs a confirmed 2"-to-1.25" step-down, send us your telescope and eyepiece setup and we'll confirm the exact part for it. The Takahashi Back Focus Guide is worth checking for the back focus target on your telescope once your full train is planned.

Frequently Asked Questions

Is it difficult to set up?

No — it's a single ring that fits directly into the 2" accessory chain it was designed for.

What is it best used for?

Adding a fixed 5 mm of spacing within a Takahashi 50.8 mm (2") accessory train.

Will it convert 2" to 1.25"?

Takahashi's catalog lists it only as a 50.8 mm sleeve fitting. Send us your setup and we'll confirm whether this or a different part gets you to 1.25".

Bottom Line

Takahashi's "50.8 Sleeve" (TKP00113) — a 5 mm ring for a 2" accessory train. If your goal is specifically a confirmed 2"-to-1.25" step-down, send us your telescope and eyepiece plans and we'll work out the right part with you.