Coronado 90 mm Double Stack Adapter Ring - AP190

Name: Coronado 90 mm Double Stack Adapter Ring - AP190
Brand: Coronado
SKU: CORO-AP190
Price: 17.99 USD
Availability: InStock
Rating: 5.0 (5 reviews)

Coronado 90 mm Double Stack Adapter Ring - AP190 - Main image

$17.99 ~~$29.99~~ In stock

Category: Telescope Accessories

Coronado 90 mm Double Stack Adapter Ring

The 90 mm Double Stack Adapter Ring is designed by Coronado and essential to double stack on an external primary Etalon for SM90.

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Express Shipping · United States: $3.99

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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (5.0 / 5 · 5 reviews)

Mia J. ★★★★★ Oct 22, 2026

This ring fit perfectly onto my SM90 etalon, and the machining is precise enough that I had zero issues with threading. The whole double stack setup came together smoothly, and the difference in contrast was immediately noticeable.

Elizabeth H. ★★★★★ Oct 21, 2026

I was worried about alignment, but this ring fit perfectly onto my SM90 etalon with zero play. The machining is precise and the anodized finish matches the rest of the setup. Now I'm getting crisp double-stack views of the sun without any hassle.

Robert W. ★★★★★ Oct 20, 2026

Installing this adapter ring was surprisingly straightforward—the threaded connection felt precise and solid when I attached it. It seated perfectly with my external etalon, making the double stack setup much easier than I expected.