ZWO D21 IR-Cut Protection Window - D21IR-CUT1

Name: ZWO D21 IR-Cut Protection Window - D21IR-CUT1
Brand: ZWO
SKU: ZWOA-D21IR-CUT1
Price: 10.88 USD
Availability: InStock
Rating: 4.4 (5 reviews)

ZWO D21 IR-Cut Protection Window - D21IR-CUT1 - Main image

ZWO D21 IR-Cut Protection Window - D21IR-CUT1 - View 2

ZWO D21 IR-Cut Protection Window - D21IR-CUT1 - View 3

$10.88 ~~$16~~ In stock

Category: Telescope Accessories

ZWO D21 IR-Cut Window

The ZWO D21 IR-Cut protection window is suitable for the ASI120 series, ASI120-S series, ASI178 series, ASI290 series, ASI224MC series, ASI385 series, ASI185MC series cameras to protect the sensor from dust and humidity.

IR-Cut D21 Window Specifications

Diameter: 21 mm

Type: UV IR-Cut Window

Thickness: 1.1 mm

Flatness: 1/4 λ

Completing your purchase

Take a moment to review your selection and total before payment.

Preparing your order

Please consider both preparation and transit when planning your purchase.

Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

View policy

Requesting a refund

Contact the store with your order details so your request can be reviewed.

Please contact us for the refund processing timeframe before returning an item.

View policy

Delivery arrangements

The available delivery services and charges are listed below.

Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

View policy

Before arranging a return

Speak with the store before arranging a return shipment.

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

View policy

Customer Reviews (4.4 / 5 · 5 reviews)

Sofia C. ★★★★★ Oct 21, 2026

I was worried about dust getting on my camera sensor, but this window solves that perfectly—the coating is clear and doesn't affect my planetary shots at all.

Daniel M. ★★★★★ Oct 20, 2026

The IR-cut filter threads on perfectly to my ASI178MC, and the clear aperture is exactly what I needed for imaging without any vignetting. I’ve left it on for two weeks of sessions and the glass still looks spotless, so it’s doing its job protecting the sensor.

George U. ★★★★☆ Oct 22, 2026

Installed this on my ASI224MC and it threaded on smoothly without any alignment issues. The IR-cut is doing its job, noticeably cleaner views of Jupiter even with some high clouds around. Only ding is I wish the packaging included a small wrench for tightening.