The Tranquillium Mattress

The Tranquillium Mattress

Regular price $799.00
Regular price $999.00 Sale price $799.00
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Discover the epitome of firm support and restful sleep with the Bed In A Box Tranquillium Mattress – a 12" marvel of comfort and stability designed to provide you with the tranquil slumber you deserve.

Crafted with a 12" multilayer foam construction, this mattress offers an exceptional blend of support and firmness. It's all about creating an ideal environment for your body to rest peacefully.

At the core of the Tranquillium Mattress is a plush CoolRest® Gel memory foam comfort layer. This layer is dedicated to ensuring you experience the perfect balance of comfort and support. It conforms to your body, providing you with a cozy surface that cradles you into restful sleep.

The Tranquillium Mattress is meticulously engineered to offer firm and supportive sleep. It's designed to cater to those who prefer a firmer sleep surface, ensuring you wake up feeling refreshed and revitalized.

To enhance your comfort further, this mattress features a soft knit Tencel™ cover. Tencel™ is renowned for its moisture management properties, helping you stay cool and dry throughout the night. Prepare for nights of undisturbed, restorative sleep.

Regardless of your preferred sleep position, the Tranquillium Mattress is here to accommodate you. Whether you're a back sleeper or side sleeper, or have your own unique sleeping style, this mattress ensures you'll find the comfort and support you need.

Proudly crafted in the USA, the Tranquillium Mattress carries both CertiPUR-US and Oeko Tex Standard 100 certifications, underscoring its commitment to quality materials and eco-friendly practices.

Invest in your sleep with confidence, as the Tranquillium Mattress comes with an impressive 20-Year Manufacturer Warranty. You're not just getting a mattress; you're investing in years of peaceful, rejuvenating slumber.

Experience the ultimate in firm support and tranquil sleep with the Bed In A Box Tranquillium Mattress – where firmness meets plush comfort, and every night is a journey to tranquility.


  • 12" Multilayer Construction
  • Firm support
  • Plush CoolRest comfort layer
  • Soft knit Tencel™ cover
  • Accommodates all sleep positions
  • Made in the USA
  • CertiPUR-US certified
  • Oeko Tex Standard 100 certified
  • 20-Year Manufacturer Warranty

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Our Haiku Concierges are experts on the products we sell and can help you find the perfect pieces for your home. We can answer whatever questions you may have. In addition, we’ve compiled some of our customers' most common questions into our FAQ. Please contact us through our online contact page or the methods below. We want to make sure you’re 100% satisfied!


Furniture over $199 Ships for Free in the Continental (Lower 48) United States of America. We do charge for shipping to Alaska, Hawaii, US Territories, and International Shipments, which is quoted on an order-by-order basis. Most furniture ships freight, which is delivered curbside to your driveway. If you need assistance getting the item into your house, carrying furniture up a flight of stairs, or more hands-on services, like assembly or white glove services, we can assist with finding the right upgrades at the right prices. Please contact our Haiku Concierges at our toll-free number, and we’re happy to help. Check out our Shipping Made Simple blog post or our Shipping Information page.

Returns and Cancellations

Most of our customers love our products at first sight, but if you change your mind or don’t like a product, we can cancel most orders up to the point they ship. Products in new, unopened, resalable condition can also be sent back in original packaging materials, but the customer is responsible for the return shipping/freight charges, per our Return Policy. Lastly, Custom Made and Made-to-Order items must be cancelled within 72 hours or are charged in full to start the production, at which point, they can’t be cancelled or returned. Please contact our Haiku Concierges at our toll-free number if you have questions.


Our catalog of furniture items is high quality and made to last. All furniture items are sold with a 1-year manufacturer’s warranty against defects in craftsmanship or functionality per our Return Policy. For your convenience, if a situation does occur regarding warranty or shipping issues, Haiku Designs will file and coordinate all claims and warranty replacements. Beyond that, it is our desire to have happy customers and earn your business anytime you have home furnishing needs. Feel free to contact us with any issues you have with a Haiku Designs purchase, and we’ll do what we can to help you resolve them.


Haiku Designs accepts all major credit cards, checks, and PayPal through our secure website checkout. You are also able to use PayPal Credit if you desire to pay over time. Generally, we’ll charge you at the time the order ships (except custom and made-to-order items which are charged ahead of starting production).

Contact Us

We'd love to hear from you. You can reach us via our online contact form, the live chat icon in the lower right, or reach us at the following:


Phone: (800) 736-7614

  • Twin: 38"W x 75"L x 12"H
  • Twin XL: 38"W x 80"L x 12"H
  • Full: 54"W x 75"L x 12"H
  • Queen: 60"W x 80"L x 12"H
  • King: 76"W x 80"L x 12"H
  • California King: 72"W x 84"L x 12"H

CertiPUR-US Certified: This foam meets strict safety and environmental standards, ensuring quality and peace of mind for your home. Rest easy knowing that cushions containing this certification are made with your well-being in mind, free from harmful chemicals. Experience lasting comfort and eco-conscious design with CertiPUR-US certified foam.

STANDARD 100 by OEKO-TEX® certified textile products have been tested for harmful substances to protect your health. Tested for Toxic Chemicals. This label certifies that every component of the product, from the fabric to the thread and accessories, has been rigorously tested against a list of up to 350 toxic chemicals.

Proudly made in the USA, this product has been manufactured in compliance with strict American regulations surrounding quality and procedure. Additionally, products made in America have a much smaller carbon footprint as they are responsible for significantly less emissions than imported products. Help support American labor while simultaneously reducing carbon emissions by purchasing American-made products.

  • Furniture Ships Free

    Furniture over $250 ships for free in the Continental (Lower 48) United States. See Shipping Page for Details.

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  • Financing Available with Affirm!

    Financing Available with Affirm! Make easy monthly payments over 3, 6 or 12 months! It's fast and easy, with no hidden fees!

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