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SafeRest
Box Spring Encasement, Split King
Split King · box spring

SafeRest Premium King 9" Thick Split Box Spring Encasement - Waterproof - Breathable, Noiseless and Vinyl Free - Fits Up to 9" - Split King

4.7 (9,033 ratings — across all sizes of this protector)

King beds usually sit on two foundations rather than one, and the gap between them is exactly the kind of place nobody cleans. This encasement is cut for split King box springs up to nine inches thick, wrapping each half in high-grade polyester on all six sides. For adjustable bases and split foundations it is the only way to close the under-mattress space completely.

$39.99
Price checked 2026-10-16

In stock

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Three layers of thinking

1

Built for split foundations

Sized for the split King configuration rather than a single slab, so each half seals properly. The inner faces that normally meet in the middle are covered too, which is where dust and pests actually settle.

2

Micro-Zipper with 360 Secure

Fine zipper teeth seal the perimeter and a Velcro flap locks the zipper traveler at the end of its run. A split base moves constantly, and the closure is engineered against exactly that.

3

Waterproof, breathable, vinyl free

High-grade polyester with a waterproof layer and no vinyl anywhere: nothing crackles, nothing smells, and the wooden frame below stays dry when a glass goes over on the nightstand.

The night test

Sealed foundations are quiet foundations. Raise and lower an adjustable base all evening and the only thing you should hear is the motor — no fabric shifting, no dust, no scratching from inside the frame.

Care

Install once and leave it under the mattress; it never enters the normal laundry rotation. If one half ever needs a wash, zip it shut, machine wash cold and tumble dry low, then reinstall with help. Full care guide →

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