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Core Down Alternative Pillow

Hypoallergenic Fill Made In USA NASA Cooling Technology

Upgrade your sleep with our Core Down Alternative Pillow. Infused with NASA-engineered tech, it offers unmatched support and softness for ultimate comfort.

- Premium NASA-engineered Outlast® fabric on both sides fights off heat.

- Filled in the USA

- Two firmness levels for perfect neck support

- OEKO-TEX® STANDARD 100 Certified Technology. Certification Number: 05.0.9235

- 300 thread count, 100% cotton outer cover

- 100% polyester non-woven lining with Outlast® Technology coating

- 100% down alternative polyester fiberfill

Standard - 20” x 26”
King - 20” x 36”

Basic Care:
Machine wash cold water on a gentle cycle with a mild detergent, and with like colors only. For best results use a front load washer. Only use non-chlorine bleach when needed. Tumble dry low heat until completely dry. Remove from dryer immediately and fluff after drying. Do not iron.

Pro Tip:
Pillows should be washed 2-4 times a year. For best results use a front load washer. When drying, use wool dryer balls to reduce dry time and improve fluffing.

All U.S. orders are shipped right to your door, free of charge.

Sleep on it, wash it, and really put it to the test for 60 nights! If you don’t love your new bedding, just return it for a full refund. No questions asked!

*Final Sale items and colors are not eligible for return, exchange, or the 60 Night Trial Period.

Core Down Alternative Pillow
On Sale from $64.00

Why You'll Love It:

Thoughtful details, inside and out.

Filled With The Good Stuff

Our Polysilk™ down alternative fiberfill mimics down without heat buildup, offering advanced comfort without hassle.

Good Enough For NASA

Built with NASA-engineered material that absorbs, stores, and releases excess heat to regulate temperature for optimal comfort all night.

Supportive Sleep

Choose Soft/Medium or Medium/Firm firmness options tailored for stomach, side, or back sleepers, ensuring ideal support for every sleeping style.

Slumber Cloud Pillow & Cover Comparisons

Different solutions all designed with temperature regulation:
Core Pillow

Cooling cotton. Structured. Classic.

UltraCool Pillow

Cool to the touch. Adaptive

Performance Pillow Cover

Zips on to pillow. Airy + breathable. Dual technologies

A close up shot of the Slumber Cloud Core Down Alternative Pillow
Detailed view of the outer fabric on the Slumber Cloud UltraCool Pillow
A close up of the Slumber Cloud Performance Pillow Cover Set made with Outlast temperature regulation technology on a moisture wicking fabric

Pillow Firmness Overview

Pick your firmness based on your typical sleeping position.

Soft / Medium

The soft-medium pillow offers the perfect support for those that prefer to sleep on their stomach and back.

Medium / Firm

The medium-firm pillow is recommended for those who regularly sleep on their side and back.

A better night’s sleep because of science.

It’s a fabric designed for NASA spacesuits up where temperatures change by 500 degrees. We think it can handle your bedroom. Learn More

The Only NASA Bedding

Our bedding utilizes Outlast®, the world’s only textile technology to have received the Certified Space Technology™ quality mark by the renowned Space Foundation.

Reduces Sweat By 50%

Our bedding provides proactive heat and moisture management, clinically proven to reduce night sweats by up to 50%. *Outlast Humidity Sleep Study

Improves Deep Sleep By 20%

Our bedding adapts to the ideal temperature of both hot and cold sleepers, proven to decrease tossing & turning and increase sleep efficiency by 20%.*Outlast Heat Sleep Study

Us vs Them

Slumber Cloud Cooling Bedding
Other "Cooling" Bamboo Products (like Buffy & Sleep Number)
Traditional Bedding (like Parachute & Brooklinen)
Proactive Temperature Regulation ?
Yes
No
No
Manages Temperature Fluctuations ?
Yes
Yes
No
Ideal for Thermally Incompatible Couples ?
Yes
No
No
Moisture Wicking Capabilities ?
Yes
Yes
No
Breathability ?
Yes
Yes
No

"Absolutely love these pillows. They are AS ADVERTISED! Super cool. Super soft. The quality is obvious the moment you take them out of the packaging."

- John M.

"Love the fabric and really does feel cool to touch at night!"

- Lauren T.

"This pillow is fantastic. I love the cotton outer fabric and its coolness. The firmness of Medium/Firm is perfect for me—this pillow rocks."

- Christopher G.

FAQs

Pick your firmness based on your typical sleeping position. The soft-medium pillow offers the perfect support for those that prefer to sleep on their stomach and back. The medium-firm pillow is recommended for those who regularly sleep on their side and back.

Yes, we want your bed to look nice and match the rest of your linens so we made sure the technology inside our pillows will still work even when used with a pillowcase.

We highly recommend using a pillow cover with your pillow. A pillow cover will reduce the wash frequency of your pillow and improve the product lifetime.

True to its name, the UltraCool pillow is going to be the "cooler" of the two pillow options. Although you will still get great temperature control with the Core Down Alternative Pillow, this is designed more for sleepers would prefer a traditional pillow with a modern temperature-regulation technology added in.