California King Box Springs & Foundations

The Serta Flat Mattress Foundation is a box spring alternative and provides the perfect support for your Serta mattress, adds 9” in height to your bed, and is designed to provide durability and long-lasting comfort. Pairing this bed base with your mattress will support it and extend its life while helping isolate the effect of your partner’s movements in bed.

Great quality and meeting all needs. Ra. Monterey, TN. Sun Aug 23 2026

We are a proud manufacturer of the finest quality box Springs, with the highest standards in durability, quality, comfort, & beauty. All of our products are made in the USA to ensure that you get only the best! This item is part of our Hollywood collection, it has the following features: this box spring is uniquely designed to give you the kind of undisturbed sleep nature intended. Wood foundation, Continental box meets federal standards 1632 and 1633 fire code.

These fit perfectly! We just needed a little extra support and our bed raised because it was too low. We purchased the 8 inch box springs. They came in two separate boxes and we’re fully put together. We simply had to place them on our bed and put the mattress back on top. Love these.. Connie. Mc Bain, MI. Thu Oct 15 2026

The Serta Low Profile Box spring offers support, durability, and reduced motion. When used with a proper supportive bed frame, it helps prevent sagging and blowing for the life of the mattress

Good support in a low profile. We also have a narrow stairway as our home is built on pilings so we wouldnt have gotten a one piece king box spring up the stairs regardless, so we were excited to see this option.. Dan. MI. Sat Sep 12 2026

Welcome to the Alwyn Home! Here we offer you the best prices for the best quality. Come have a look at our latest Split Fully Assembled Box Spring for Mattress from our Alwyn Home collection. This design is handcrafted so that you forget back pains and discomfort forever. Lay down your favorite mattress on our box spring to enjoy the beautiful sleep you always wanted. The equally distant slats and wood frame do not let the frame loosen up and are strong enough to handle various kinds of duress. You don’t need to worry about a squeaky bed frame ever again. The excellent packaging and design of the box spring are pre-assembled, just the perfect fit for your bedroom. The product is lightweight even as a traditional box spring and lets you have these benefits in assorted sizes namely: Twin, Twin-XL, Full, Full XL, Queen, King, and California King. We have twin profiles of the product in 4” and 8” thicknesses crafted just for your needs.

Still holding up after 3 years. Very good for the price. Deanna. Thu Sep 24 2026

Premium 5 Inch Box Spring features durable heavy-duty metal construction with strong load-bearing capacity, delivering long-lasting stability and reliable support for a restful night’s sleep. Boasting a sleek low-profile design, it fits seamlessly with any bedroom decor while saving space beautifully. This noise-free mattress foundation eliminates squeaks and rattles for an ultra-quiet sleeping experience. Designed for effortless quick assembly and fitted with a premium fabric cover, it not only adds elegant style but also shields the base from dust and daily wear. Available in twin, twin xl, queen, and king size box spring options, it can perfectly serve as your ideal twin bed frame, queen bed frame and king size bed frame foundation to match various mattress sizes.

Sturdy and quiet. Easy assembly. Pamela. Pomona, CA. Tue Jul 07 2026